You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
The various Is methods (IsPrivate, IsLoopback, etc) did not work as expected for IPv4-mapped IPv6 addresses, returning false for addresses which would return true in their traditional IPv4 forms.
Affected range
<1.19.9
Fixed version
1.19.9
Description
Not all valid JavaScript whitespace characters are considered to be whitespace. Templates containing whitespace characters outside of the character set "\t\n\f\r\u0020\u2028\u2029" in JavaScript contexts that also contain actions may not be properly sanitized during execution.
Affected range
<1.19.8
Fixed version
1.19.8
Description
Templates do not properly consider backticks (`) as Javascript string delimiters, and do not escape them as expected.
Backticks are used, since ES6, for JS template literals. If a template contains a Go template action within a Javascript template literal, the contents of the action can be used to terminate the literal, injecting arbitrary Javascript code into the Go template.
As ES6 template literals are rather complex, and themselves can do string interpolation, the decision was made to simply disallow Go template actions from being used inside of them (e.g. "var a = {{.}}"), since there is no obviously safe way to allow this behavior. This takes the same approach as github.com/google/safehtml.
With fix, Template.Parse returns an Error when it encounters templates like this, with an ErrorCode of value 12. This ErrorCode is currently unexported, but will be exported in the release of Go 1.21.
Users who rely on the previous behavior can re-enable it using the GODEBUG flag jstmpllitinterp=1, with the caveat that backticks will now be escaped. This should be used with caution.
Affected range
<1.19.10
Fixed version
1.19.10
Description
On Unix platforms, the Go runtime does not behave differently when a binary is run with the setuid/setgid bits. This can be dangerous in certain cases, such as when dumping memory state, or assuming the status of standard i/o file descriptors.
If a setuid/setgid binary is executed with standard I/O file descriptors closed, opening any files can result in unexpected content being read or written with elevated privileges. Similarly, if a setuid/setgid program is terminated, either via panic or signal, it may leak the contents of its registers.
Affected range
<1.22.7
Fixed version
1.22.7
Description
Calling Parse on a "// +build" build tag line with deeply nested expressions can cause a panic due to stack exhaustion.
Affected range
<1.22.7
Fixed version
1.22.7
Description
Calling Decoder.Decode on a message which contains deeply nested structures can cause a panic due to stack exhaustion. This is a follow-up to CVE-2022-30635.
Affected range
<1.21.12
Fixed version
1.21.12
Description
The net/http HTTP/1.1 client mishandled the case where a server responds to a request with an "Expect: 100-continue" header with a non-informational (200 or higher) status. This mishandling could leave a client connection in an invalid state, where the next request sent on the connection will fail.
An attacker sending a request to a net/http/httputil.ReverseProxy proxy can exploit this mishandling to cause a denial of service by sending "Expect: 100-continue" requests which elicit a non-informational response from the backend. Each such request leaves the proxy with an invalid connection, and causes one subsequent request using that connection to fail.
Affected range
<1.21.8
Fixed version
1.21.8
Description
The ParseAddressList function incorrectly handles comments (text within parentheses) within display names. Since this is a misalignment with conforming address parsers, it can result in different trust decisions being made by programs using different parsers.
Affected range
<1.21.9
Fixed version
1.21.9
Description
An attacker may cause an HTTP/2 endpoint to read arbitrary amounts of header data by sending an excessive number of CONTINUATION frames.
Maintaining HPACK state requires parsing and processing all HEADERS and CONTINUATION frames on a connection. When a request's headers exceed MaxHeaderBytes, no memory is allocated to store the excess headers, but they are still parsed.
This permits an attacker to cause an HTTP/2 endpoint to read arbitrary amounts of header data, all associated with a request which is going to be rejected. These headers can include Huffman-encoded data which is significantly more expensive for the receiver to decode than for an attacker to send.
The fix sets a limit on the amount of excess header frames we will process before closing a connection.
Affected range
<1.20.0
Fixed version
1.20.0
Description
Before Go 1.20, the RSA based TLS key exchanges used the math/big library, which is not constant time. RSA blinding was applied to prevent timing attacks, but analysis shows this may not have been fully effective. In particular it appears as if the removal of PKCS#1 padding may leak timing information, which in turn could be used to recover session key bits.
In Go 1.20, the crypto/tls library switched to a fully constant time RSA implementation, which we do not believe exhibits any timing side channels.
Affected range
<1.20.11
Fixed version
1.20.11
Description
The filepath package does not recognize paths with a ??\ prefix as special.
On Windows, a path beginning with ??\ is a Root Local Device path equivalent to a path beginning with \?. Paths with a ??\ prefix may be used to access arbitrary locations on the system. For example, the path ??\c:\x is equivalent to the more common path c:\x.
Before fix, Clean could convert a rooted path such as \a..??\b into the root local device path ??\b. Clean will now convert this to .??\b.
Similarly, Join(, ??, b) could convert a seemingly innocent sequence of path elements into the root local device path ??\b. Join will now convert this to .??\b.
In addition, with fix, IsAbs now correctly reports paths beginning with ??\ as absolute, and VolumeName correctly reports the ??\ prefix as a volume name.
UPDATE: Go 1.20.11 and Go 1.21.4 inadvertently changed the definition of the volume name in Windows paths starting with ?, resulting in filepath.Clean(?\c:) returning ?\c: rather than ?\c:\ (among other effects). The previous behavior has been restored.
Affected range
<1.20.10
Fixed version
1.20.10
Description
A malicious HTTP/2 client which rapidly creates requests and immediately resets them can cause excessive server resource consumption. While the total number of requests is bounded by the http2.Server.MaxConcurrentStreams setting, resetting an in-progress request allows the attacker to create a new request while the existing one is still executing.
With the fix applied, HTTP/2 servers now bound the number of simultaneously executing handler goroutines to the stream concurrency limit (MaxConcurrentStreams). New requests arriving when at the limit (which can only happen after the client has reset an existing, in-flight request) will be queued until a handler exits. If the request queue grows too large, the server will terminate the connection.
This issue is also fixed in golang.org/x/net/http2 for users manually configuring HTTP/2.
The default stream concurrency limit is 250 streams (requests) per HTTP/2 connection. This value may be adjusted using the golang.org/x/net/http2 package; see the Server.MaxConcurrentStreams setting and the ConfigureServer function.
Affected range
<1.20.10
Fixed version
1.20.10
Description
A malicious HTTP/2 client which rapidly creates requests and immediately resets them can cause excessive server resource consumption. While the total number of requests is bounded by the http2.Server.MaxConcurrentStreams setting, resetting an in-progress request allows the attacker to create a new request while the existing one is still executing.
With the fix applied, HTTP/2 servers now bound the number of simultaneously executing handler goroutines to the stream concurrency limit (MaxConcurrentStreams). New requests arriving when at the limit (which can only happen after the client has reset an existing, in-flight request) will be queued until a handler exits. If the request queue grows too large, the server will terminate the connection.
This issue is also fixed in golang.org/x/net/http2 for users manually configuring HTTP/2.
The default stream concurrency limit is 250 streams (requests) per HTTP/2 connection. This value may be adjusted using the golang.org/x/net/http2 package; see the Server.MaxConcurrentStreams setting and the ConfigureServer function.
Affected range
<1.19.8
Fixed version
1.19.8
Description
Calling any of the Parse functions on Go source code which contains //line directives with very large line numbers can cause an infinite loop due to integer overflow.
Affected range
<1.19.8
Fixed version
1.19.8
Description
Multipart form parsing can consume large amounts of CPU and memory when processing form inputs containing very large numbers of parts.
This stems from several causes:
mime/multipart.Reader.ReadForm limits the total memory a parsed multipart form can consume. ReadForm can undercount the amount of memory consumed, leading it to accept larger inputs than intended.
Limiting total memory does not account for increased pressure on the garbage collector from large numbers of small allocations in forms with many parts.
ReadForm can allocate a large number of short-lived buffers, further increasing pressure on the garbage collector.
The combination of these factors can permit an attacker to cause an program that parses multipart forms to consume large amounts of CPU and memory, potentially resulting in a denial of service. This affects programs that use mime/multipart.Reader.ReadForm, as well as form parsing in the net/http package with the Request methods FormFile, FormValue, ParseMultipartForm, and PostFormValue.
With fix, ReadForm now does a better job of estimating the memory consumption of parsed forms, and performs many fewer short-lived allocations.
In addition, the fixed mime/multipart.Reader imposes the following limits on the size of parsed forms:
Forms parsed with ReadForm may contain no more than 1000 parts. This limit may be adjusted with the environment variable GODEBUG=multipartmaxparts=.
Form parts parsed with NextPart and NextRawPart may contain no more than 10,000 header fields. In addition, forms parsed with ReadForm may contain no more than 10,000 header fields across all parts. This limit may be adjusted with the environment variable GODEBUG=multipartmaxheaders=.
Affected range
<1.19.8
Fixed version
1.19.8
Description
HTTP and MIME header parsing can allocate large amounts of memory, even when parsing small inputs, potentially leading to a denial of service.
Certain unusual patterns of input data can cause the common function used to parse HTTP and MIME headers to allocate substantially more memory than required to hold the parsed headers. An attacker can exploit this behavior to cause an HTTP server to allocate large amounts of memory from a small request, potentially leading to memory exhaustion and a denial of service.
With fix, header parsing now correctly allocates only the memory required to hold parsed headers.
Affected range
<1.19.6
Fixed version
1.19.6
Description
A denial of service is possible from excessive resource consumption in net/http and mime/multipart.
Multipart form parsing with mime/multipart.Reader.ReadForm can consume largely unlimited amounts of memory and disk files. This also affects form parsing in the net/http package with the Request methods FormFile, FormValue, ParseMultipartForm, and PostFormValue.
ReadForm takes a maxMemory parameter, and is documented as storing "up to maxMemory bytes +10MB (reserved for non-file parts) in memory". File parts which cannot be stored in memory are stored on disk in temporary files. The unconfigurable 10MB reserved for non-file parts is excessively large and can potentially open a denial of service vector on its own. However, ReadForm did not properly account for all memory consumed by a parsed form, such as map entry overhead, part names, and MIME headers, permitting a maliciously crafted form to consume well over 10MB. In addition, ReadForm contained no limit on the number of disk files created, permitting a relatively small request body to create a large number of disk temporary files.
With fix, ReadForm now properly accounts for various forms of memory overhead, and should now stay within its documented limit of 10MB + maxMemory bytes of memory consumption. Users should still be aware that this limit is high and may still be hazardous.
In addition, ReadForm now creates at most one on-disk temporary file, combining multiple form parts into a single temporary file. The mime/multipart.File interface type's documentation states, "If stored on disk, the File's underlying concrete type will be an *os.File.". This is no longer the case when a form contains more than one file part, due to this coalescing of parts into a single file. The previous behavior of using distinct files for each form part may be reenabled with the environment variable GODEBUG=multipartfiles=distinct.
Users should be aware that multipart.ReadForm and the http.Request methods that call it do not limit the amount of disk consumed by temporary files. Callers can limit the size of form data with http.MaxBytesReader.
Affected range
<1.19.6
Fixed version
1.19.6
Description
Large handshake records may cause panics in crypto/tls.
Both clients and servers may send large TLS handshake records which cause servers and clients, respectively, to panic when attempting to construct responses.
This affects all TLS 1.3 clients, TLS 1.2 clients which explicitly enable session resumption (by setting Config.ClientSessionCache to a non-nil value), and TLS 1.3 servers which request client certificates (by setting Config.ClientAuth >= RequestClientCert).
Affected range
<1.19.6
Fixed version
1.19.6
Description
A maliciously crafted HTTP/2 stream could cause excessive CPU consumption in the HPACK decoder, sufficient to cause a denial of service from a small number of small requests.
Affected range
<1.19.6
Fixed version
1.19.6
Description
A path traversal vulnerability exists in filepath.Clean on Windows.
On Windows, the filepath.Clean function could transform an invalid path such as "a/../c:/b" into the valid path "c:\b". This transformation of a relative (if invalid) path into an absolute path could enable a directory traversal attack.
After fix, the filepath.Clean function transforms this path into the relative (but still invalid) path ".\c:\b".
Affected range
>=1.19.0-0 <1.19.4
Fixed version
1.19.4
Description
On Windows, restricted files can be accessed via os.DirFS and http.Dir.
The os.DirFS function and http.Dir type provide access to a tree of files rooted at a given directory. These functions permit access to Windows device files under that root. For example, os.DirFS("C:/tmp").Open("COM1") opens the COM1 device. Both os.DirFS and http.Dir only provide read-only filesystem access.
In addition, on Windows, an os.DirFS for the directory (the root of the current drive) can permit a maliciously crafted path to escape from the drive and access any path on the system.
With fix applied, the behavior of os.DirFS("") has changed. Previously, an empty root was treated equivalently to "/", so os.DirFS("").Open("tmp") would open the path "/tmp". This now returns an error.
Affected range
>=1.19.0-0 <1.19.3
Fixed version
1.19.3
Description
Due to unsanitized NUL values, attackers may be able to maliciously set environment variables on Windows.
In syscall.StartProcess and os/exec.Cmd, invalid environment variable values containing NUL values are not properly checked for. A malicious environment variable value can exploit this behavior to set a value for a different environment variable. For example, the environment variable string "A=B\x00C=D" sets the variables "A=B" and "C=D".
Affected range
>=1.19.0-0 <1.19.2
Fixed version
1.19.2
Description
Programs which compile regular expressions from untrusted sources may be vulnerable to memory exhaustion or denial of service.
The parsed regexp representation is linear in the size of the input, but in some cases the constant factor can be as high as 40,000, making relatively small regexps consume much larger amounts of memory.
After fix, each regexp being parsed is limited to a 256 MB memory footprint. Regular expressions whose representation would use more space than that are rejected. Normal use of regular expressions is unaffected.
Affected range
>=1.19.0-0 <1.19.1
Fixed version
1.19.1
Description
JoinPath and URL.JoinPath do not remove ../ path elements appended to a relative path. For example, JoinPath("https://go.dev", "../go") returns the URL "https://go.dev/../go", despite the JoinPath documentation stating that ../ path elements are removed from the result.
Affected range
<1.22.7
Fixed version
1.22.7
Description
Calling Decoder.Decode on a message which contains deeply nested structures can cause a panic due to stack exhaustion. This is a follow-up to CVE-2022-30635.
Affected range
>=1.19.0-0 <1.19.2
Fixed version
1.19.2
Description
Requests forwarded by ReverseProxy include the raw query parameters from the inbound request, including unparsable parameters rejected by net/http. This could permit query parameter smuggling when a Go proxy forwards a parameter with an unparsable value.
After fix, ReverseProxy sanitizes the query parameters in the forwarded query when the outbound request's Form field is set after the ReverseProxy. Director function returns, indicating that the proxy has parsed the query parameters. Proxies which do not parse query parameters continue to forward the original query parameters unchanged.
Affected range
>=1.19.0-0 <1.19.2
Fixed version
1.19.2
Description
Reader.Read does not set a limit on the maximum size of file headers. A maliciously crafted archive could cause Read to allocate unbounded amounts of memory, potentially causing resource exhaustion or panics. After fix, Reader.Read limits the maximum size of header blocks to 1 MiB.
Affected range
>=1.19.0-0 <1.19.1
Fixed version
1.19.1
Description
HTTP/2 server connections can hang forever waiting for a clean shutdown that was preempted by a fatal error. This condition can be exploited by a malicious client to cause a denial of service.
Affected range
<1.19.9
Fixed version
1.19.9
Description
Templates containing actions in unquoted HTML attributes (e.g. "attr={{.}}") executed with empty input can result in output with unexpected results when parsed due to HTML normalization rules. This may allow injection of arbitrary attributes into tags.
Affected range
<1.19.9
Fixed version
1.19.9
Description
Angle brackets (<>) are not considered dangerous characters when inserted into CSS contexts. Templates containing multiple actions separated by a '/' character can result in unexpectedly closing the CSS context and allowing for injection of unexpected HTML, if executed with untrusted input.
Affected range
<1.21.8
Fixed version
1.21.8
Description
When parsing a multipart form (either explicitly with Request.ParseMultipartForm or implicitly with Request.FormValue, Request.PostFormValue, or Request.FormFile), limits on the total size of the parsed form were not applied to the memory consumed while reading a single form line. This permits a maliciously crafted input containing very long lines to cause allocation of arbitrarily large amounts of memory, potentially leading to memory exhaustion.
With fix, the ParseMultipartForm function now correctly limits the maximum size of form lines.
Affected range
<1.19.11
Fixed version
1.19.11
Description
The HTTP/1 client does not fully validate the contents of the Host header. A maliciously crafted Host header can inject additional headers or entire requests.
With fix, the HTTP/1 client now refuses to send requests containing an invalid Request.Host or Request.URL.Host value.
Affected range
<1.20.8
Fixed version
1.20.8
Description
The html/template package does not apply the proper rules for handling occurrences of "<script", "<!--", and "</script" within JS literals in <script> contexts. This may cause the template parser to improperly consider script contexts to be terminated early, causing actions to be improperly escaped. This could be leveraged to perform an XSS attack.
Affected range
<1.20.8
Fixed version
1.20.8
Description
The html/template package does not properly handle HTML-like "" comment tokens, nor hashbang "#!" comment tokens, in <script> contexts. This may cause the template parser to improperly interpret the contents of <script> contexts, causing actions to be improperly escaped. This may be leveraged to perform an XSS attack.
Affected range
<1.21.8
Fixed version
1.21.8
Description
Verifying a certificate chain which contains a certificate with an unknown public key algorithm will cause Certificate.Verify to panic.
This affects all crypto/tls clients, and servers that set Config.ClientAuth to VerifyClientCertIfGiven or RequireAndVerifyClientCert. The default behavior is for TLS servers to not verify client certificates.
Affected range
<1.21.11
Fixed version
1.21.11
Description
The archive/zip package's handling of certain types of invalid zip files differs from the behavior of most zip implementations. This misalignment could be exploited to create an zip file with contents that vary depending on the implementation reading the file. The archive/zip package now rejects files containing these errors.
Affected range
<1.20.11
Fixed version
1.20.11
Description
On Windows, The IsLocal function does not correctly detect reserved device names in some cases.
Reserved names followed by spaces, such as "COM1 ", and reserved names "COM" and "LPT" followed by superscript 1, 2, or 3, are incorrectly reported as local.
With fix, IsLocal now correctly reports these names as non-local.
Affected range
<1.20.12
Fixed version
1.20.12
Description
A malicious HTTP sender can use chunk extensions to cause a receiver reading from a request or response body to read many more bytes from the network than are in the body.
A malicious HTTP client can further exploit this to cause a server to automatically read a large amount of data (up to about 1GiB) when a handler fails to read the entire body of a request.
Chunk extensions are a little-used HTTP feature which permit including additional metadata in a request or response body sent using the chunked encoding. The net/http chunked encoding reader discards this metadata. A sender can exploit this by inserting a large metadata segment with each byte transferred. The chunk reader now produces an error if the ratio of real body to encoded bytes grows too small.
Affected range
<1.19.12
Fixed version
1.19.12
Description
Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures.
With fix, the size of RSA keys transmitted during handshakes is restricted to <= 8192 bits.
Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable.
Affected range
<1.19.7
Fixed version
1.19.7
Description
The ScalarMult and ScalarBaseMult methods of the P256 Curve may return an incorrect result if called with some specific unreduced scalars (a scalar larger than the order of the curve).
This does not impact usages of crypto/ecdsa or crypto/ecdh.
Affected range
>=1.19.0-0 <1.19.4
Fixed version
1.19.4
Description
An attacker can cause excessive memory growth in a Go server accepting HTTP/2 requests.
HTTP/2 server connections contain a cache of HTTP header keys sent by the client. While the total number of entries in this cache is capped, an attacker sending very large keys can cause the server to allocate approximately 64 MiB per open connection.
Affected range
<1.22.7
Fixed version
1.22.7
Description
Calling any of the Parse functions on Go source code which contains deeply nested literals can cause a panic due to stack exhaustion.
Affected range
<1.21.8
Fixed version
1.21.8
Description
When following an HTTP redirect to a domain which is not a subdomain match or exact match of the initial domain, an http.Client does not forward sensitive headers such as "Authorization" or "Cookie". For example, a redirect from foo.com to www.foo.com will forward the Authorization header, but a redirect to bar.com will not.
A maliciously crafted HTTP redirect could cause sensitive headers to be unexpectedly forwarded.
Affected range
<1.21.8
Fixed version
1.21.8
Description
If errors returned from MarshalJSON methods contain user controlled data, they may be used to break the contextual auto-escaping behavior of the html/template package, allowing for subsequent actions to inject unexpected content into templates.
A security vulnerability has been detected in certain versions of Docker Engine, which could allow an attacker to bypass authorization plugins (AuthZ) under specific circumstances. The base likelihood of this being exploited is low. This advisory outlines the issue, identifies the affected versions, and provides remediation steps for impacted users.
Impact
Using a specially-crafted API request, an Engine API client could make the daemon forward the request or response to an authorization plugin without the body. In certain circumstances, the authorization plugin may allow a request which it would have otherwise denied if the body had been forwarded to it.
A security issue was discovered In 2018, where an attacker could bypass AuthZ plugins using a specially crafted API request. This could lead to unauthorized actions, including privilege escalation. Although this issue was fixed in Docker Engine v18.09.1 in January 2019, the fix was not carried forward to later major versions, resulting in a regression. Anyone who depends on authorization plugins that introspect the request and/or response body to make access control decisions is potentially impacted.
Docker EE v19.03.x and all versions of Mirantis Container Runtime are not vulnerable.
Vulnerability details
AuthZ bypass and privilege escalation: An attacker could exploit a bypass using an API request with Content-Length set to 0, causing the Docker daemon to forward the request without the body to the AuthZ plugin, which might approve the request incorrectly.
Initial fix: The issue was fixed in Docker Engine v18.09.1 January 2019..
Regression: The fix was not included in Docker Engine v19.03 or newer versions. This was identified in April 2024 and patches were released for the affected versions on July 23, 2024. The issue was assigned CVE-2024-41110.
Patches
docker-ce v27.1.1 containes patches to fix the vulnerability.
Patches have also been merged into the master, 19.0, 20.0, 23.0, 24.0, 25.0, 26.0, and 26.1 release branches.
Remediation steps
If you are running an affected version, update to the most recent patched version.
Mitigation if unable to update immediately:
Avoid using AuthZ plugins.
Restrict access to the Docker API to trusted parties, following the principle of least privilege.
The classic builder cache system is prone to cache poisoning if the image is built FROM scratch.
Also, changes to some instructions (most important being HEALTHCHECK and ONBUILD) would not cause a cache miss.
An attacker with the knowledge of the Dockerfile someone is using could poison their cache by making them pull a specially crafted image that would be considered as a valid cache candidate for some build steps.
For example, an attacker could create an image that is considered as a valid cache candidate for:
FROM scratch
MAINTAINER Pawel
when in fact the malicious image used as a cache would be an image built from a different Dockerfile.
In the second case, the attacker could for example substitute a different HEALTCHECK command.
Impact
23.0+ users are only affected if they explicitly opted out of Buildkit (DOCKER_BUILDKIT=0 environment variable) or are using the /build API endpoint (which uses the classic builder by default).
All users on versions older than 23.0 could be impacted. An example could be a CI with a shared cache, or just a regular Docker user pulling a malicious image due to misspelling/typosquatting.
Image build API endpoint (/build) and ImageBuild function from github.com/docker/docker/client is also affected as it the uses classic builder by default.
Patches
Patches are included in Moby releases:
v25.0.2
v24.0.9
v23.0.10
Workarounds
Use --no-cache or use Buildkit if possible (DOCKER_BUILDKIT=1, it's default on 23.0+ assuming that the buildx plugin is installed).
Use Version = types.BuilderBuildKit or NoCache = true in ImageBuildOptions for ImageBuild call.
Incorrect Resource Transfer Between Spheres
Affected range
<23.0.11
Fixed version
23.0.11
CVSS Score
5.9
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Description
Moby is an open source container framework originally developed by Docker Inc. as Docker. It is a key component of Docker Engine, Docker Desktop, and other distributions of container tooling or runtimes. As a batteries-included container runtime, Moby comes with a built-in networking implementation that enables communication between containers, and between containers and external resources.
Moby's networking implementation allows for creating and using many networks, each with their own subnet and gateway. This feature is frequently referred to as custom networks, as each network can have a different driver, set of parameters, and thus behaviors. When creating a network, the --internal flag is used to designate a network as internal. The internal attribute in a docker-compose.yml file may also be used to mark a network internal, and other API clients may specify the internal parameter as well.
When containers with networking are created, they are assigned unique network interfaces and IP addresses (typically from a non-routable RFC 1918 subnet). The root network namespace (hereafter referred to as the 'host') serves as a router for non-internal networks, with a gateway IP that provides SNAT/DNAT to/from container IPs.
Containers on an internal network may communicate between each other, but are precluded from communicating with any networks the host has access to (LAN or WAN) as no default route is configured, and firewall rules are set up to drop all outgoing traffic. Communication with the gateway IP address (and thus appropriately configured host services) is possible, and the host may communicate with any container IP directly.
In addition to configuring the Linux kernel's various networking features to enable container networking, dockerd directly provides some services to container networks. Principal among these is serving as a resolver, enabling service discovery (looking up other containers on the network by name), and resolution of names from an upstream resolver.
When a DNS request for a name that does not correspond to a container is received, the request is forwarded to the configured upstream resolver (by default, the host's configured resolver). This request is made from the container network namespace: the level of access and routing of traffic is the same as if the request was made by the container itself.
As a consequence of this design, containers solely attached to internal network(s) will be unable to resolve names using the upstream resolver, as the container itself is unable to communicate with that nameserver. Only the names of containers also attached to the internal network are able to be resolved.
Many systems will run a local forwarding DNS resolver, typically present on a loopback address (127.0.0.0/8), such as systemd-resolved or dnsmasq. Common loopback address examples include 127.0.0.1 or 127.0.0.53. As the host and any containers have separate loopback devices, a consequence of the design described above is that containers are unable to resolve names from the host's configured resolver, as they cannot reach these addresses on the host loopback device.
To bridge this gap, and to allow containers to properly resolve names even when a local forwarding resolver is used on a loopback address, dockerd will detect this scenario and instead forward DNS requests from the host/root network namespace. The loopback resolver will then forward the requests to its configured upstream resolvers, as expected.
Impact
Because dockerd will forward DNS requests to the host loopback device, bypassing the container network namespace's normal routing semantics entirely, internal networks can unexpectedly forward DNS requests to an external nameserver.
By registering a domain for which they control the authoritative nameservers, an attacker could arrange for a compromised container to exfiltrate data by encoding it in DNS queries that will eventually be answered by their nameservers. For example, if the domain evil.example was registered, the authoritative nameserver(s) for that domain could (eventually and indirectly) receive a request for this-is-a-secret.evil.example.
Docker Desktop is not affected, as Docker Desktop always runs an internal resolver on a RFC 1918 address.
Patches
Moby releases 26.0.0-rc3, 25.0.5 (released) and 23.0.11 (to be released) are patched to prevent forwarding DNS requests from internal networks.
Workarounds
Run containers intended to be solely attached to internal networks with a custom upstream address (--dns argument to docker run, or API equivalent), which will force all upstream DNS queries to be resolved from the container network namespace.
Background
yair zak originally reported this issue to the Docker security team.
The official documentation claims that "the --internal flag that will completely isolate containers on a network from any communications external to that network," which necessitated this advisory and CVE.
github.com/opencontainers/runc1.1.12 (golang)
pkg:golang/github.com/opencontainers/runc@1.1.12
OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
Affected range
<1.2.0-rc.1
Fixed version
1.2.0-rc.1
CVSS Score
7.2
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Description
Withdrawn Advisory
This advisory has been withdrawn because it was incorrectly attributed to runc. Please see the issue here for more information.
Original Description
A flaw was found in cri-o, where an arbitrary systemd property can be injected via a Pod annotation. Any user who can create a pod with an arbitrary annotation may perform an arbitrary action on the host system. This issue has its root in how runc handles Config Annotations lists.
runc 1.1.13 and earlier as well as 1.2.0-rc2 and earlier can be tricked into
creating empty files or directories in arbitrary locations in the host
filesystem by sharing a volume between two containers and exploiting a race
with os.MkdirAll. While this can be used to create empty files, existing
files will not be truncated.
An attacker must have the ability to start containers using some kind of custom
volume configuration. Containers using user namespaces are still affected, but
the scope of places an attacker can create inodes can be significantly reduced.
Sufficiently strict LSM policies (SELinux/Apparmor) can also in principle block
this attack -- we suspect the industry standard SELinux policy may restrict
this attack's scope but the exact scope of protection hasn't been analysed.
This is exploitable using runc directly as well as through Docker and
Kubernetes.
The CVSS score for this vulnerability is
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N (Low severity, 3.6).
Workarounds
Using user namespaces restricts this attack fairly significantly such that the
attacker can only create inodes in directories that the remapped root
user/group has write access to. Unless the root user is remapped to an actual
user on the host (such as with rootless containers that don't use
/etc/sub[ug]id), this in practice means that an attacker would only be able to
create inodes in world-writable directories.
A strict enough SELinux or AppArmor policy could in principle also restrict the
scope if a specific label is applied to the runc runtime, though we haven't
thoroughly tested to what extent the standard existing policies block this
attack nor what exact policies are needed to sufficiently restrict this attack.
The protojson.Unmarshal function can enter an infinite loop when unmarshaling certain forms of invalid JSON. This condition can occur when unmarshaling into a message which contains a google.protobuf.Any value, or when the UnmarshalOptions.DiscardUnknown option is set.
golang.org/x/net0.19.0 (golang)
pkg:golang/golang.org/x/net@0.19.0
Uncontrolled Resource Consumption
Affected range
<0.23.0
Fixed version
0.23.0
CVSS Score
5.3
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Description
An attacker may cause an HTTP/2 endpoint to read arbitrary amounts of header data by sending an excessive number of CONTINUATION frames. Maintaining HPACK state requires parsing and processing all HEADERS and CONTINUATION frames on a connection. When a request's headers exceed MaxHeaderBytes, no memory is allocated to store the excess headers, but they are still parsed. This permits an attacker to cause an HTTP/2 endpoint to read arbitrary amounts of header data, all associated with a request which is going to be rejected. These headers can include Huffman-encoded data which is significantly more expensive for the receiver to decode than for an attacker to send. The fix sets a limit on the amount of excess header frames we will process before closing a connection.
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This PR contains the following updates:
0.49.1->0.49.2Warning
Some dependencies could not be looked up. Check the Dependency Dashboard for more information.
Release Notes
google/cadvisor (google/cadvisor)
v0.49.2Compare Source
What's Changed
Full Changelog: google/cadvisor@v0.49.1...v0.49.2
Configuration
📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).
🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.
♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.
🔕 Ignore: Close this PR and you won't be reminded about this update again.
This PR has been generated by Renovate Bot.