Exploit prevention ssrf blocking (#4372)

---------

Co-authored-by: Igor Unanua <igor.unanua@datadoghq.com>
Co-authored-by: simon-id <simon.id@datadoghq.com>

.github/workflows/appsec.yml

@@ -246,3 +246,13 @@ jobs:
       - uses: ./.github/actions/node/latest
       - run: yarn test:appsec:plugins:ci
       - uses: codecov/codecov-action@v3
+
+  integration:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - run: yarn install
+      - uses: ./.github/actions/node/oldest
+      - run: yarn test:integration:appsec
+      - uses: ./.github/actions/node/latest
+      - run: yarn test:integration:appsec

integration-tests/appsec/index.spec.js

@@ -0,0 +1,342 @@
+'use strict'
+
+const getPort = require('get-port')
+const path = require('path')
+const Axios = require('axios')
+const { assert } = require('chai')
+const { createSandbox, FakeAgent, spawnProc } = require('../helpers')
+
+describe('RASP', () => {
+  let axios, sandbox, cwd, appPort, appFile, agent, proc, stdioHandler
+
+  function stdOutputHandler (data) {
+    stdioHandler && stdioHandler(data)
+  }
+
+  before(async () => {
+    sandbox = await createSandbox(['express', 'axios'])
+    appPort = await getPort()
+    cwd = sandbox.folder
+    appFile = path.join(cwd, 'appsec/rasp/index.js')
+    axios = Axios.create({
+      baseURL: `http://localhost:${appPort}`
+    })
+  })
+
+  after(async () => {
+    await sandbox.remove()
+  })
+
+  function startServer (abortOnUncaughtException) {
+    beforeEach(async () => {
+      let execArgv = process.execArgv
+      if (abortOnUncaughtException) {
+        execArgv = ['--abort-on-uncaught-exception', ...execArgv]
+      }
+      agent = await new FakeAgent().start()
+      proc = await spawnProc(appFile, {
+        cwd,
+        execArgv,
+        env: {
+          DD_TRACE_AGENT_PORT: agent.port,
+          APP_PORT: appPort,
+          DD_APPSEC_ENABLED: true,
+          DD_APPSEC_RASP_ENABLED: true,
+          DD_APPSEC_RULES: path.join(cwd, 'appsec/rasp/rasp_rules.json')
+        }
+      }, stdOutputHandler, stdOutputHandler)
+    })
+
+    afterEach(async () => {
+      proc.kill()
+      await agent.stop()
+    })
+  }
+
+  async function assertExploitDetected () {
+    await agent.assertMessageReceived(({ headers, payload }) => {
+      assert.property(payload[0][0].meta, '_dd.appsec.json')
+      assert.include(payload[0][0].meta['_dd.appsec.json'], '"test-rule-id-2"')
+    })
+  }
+
+  describe('--abort-on-uncaught-exception is not configured', () => {
+    startServer(false)
+
+    async function testNotCrashedAfterBlocking (path) {
+      let hasOutput = false
+      stdioHandler = () => {
+        hasOutput = true
+      }
+
+      try {
+        await axios.get(`${path}?host=localhost/ifconfig.pro`)
+
+        assert.fail('Request should have failed')
+      } catch (e) {
+        if (!e.response) {
+          throw e
+        }
+
+        assert.strictEqual(e.response.status, 403)
+        await assertExploitDetected()
+      }
+
+      return new Promise((resolve, reject) => {
+        setTimeout(() => {
+          if (hasOutput) {
+            reject(new Error('Unexpected output in stdout/stderr after blocking request'))
+          } else {
+            resolve()
+          }
+        }, 50)
+      })
+    }
+
+    async function testCustomErrorHandlerIsNotExecuted (path) {
+      let hasOutput = false
+      try {
+        stdioHandler = () => {
+          hasOutput = true
+        }
+
+        await axios.get(`${path}?host=localhost/ifconfig.pro`)
+
+        assert.fail('Request should have failed')
+      } catch (e) {
+        if (!e.response) {
+          throw e
+        }
+
+        assert.strictEqual(e.response.status, 403)
+        await assertExploitDetected()
+
+        return new Promise((resolve, reject) => {
+          setTimeout(() => {
+            if (hasOutput) {
+              reject(new Error('uncaughtExceptionCaptureCallback executed'))
+            } else {
+              resolve()
+            }
+          }, 10)
+        })
+      }
+    }
+
+    async function testAppCrashesAsExpected () {
+      let hasOutput = false
+      stdioHandler = () => {
+        hasOutput = true
+      }
+
+      try {
+        await axios.get('/crash')
+      } catch (e) {
+        return new Promise((resolve, reject) => {
+          setTimeout(() => {
+            if (hasOutput) {
+              resolve()
+            } else {
+              reject(new Error('Output expected after crash'))
+            }
+          }, 50)
+        })
+      }
+
+      assert.fail('Request should have failed')
+    }
+
+    describe('ssrf', () => {
+      it('should crash when error is not an AbortError', async () => {
+        await testAppCrashesAsExpected()
+      })
+
+      it('should not crash when customer has his own setUncaughtExceptionCaptureCallback', async () => {
+        let hasOutput = false
+        stdioHandler = () => {
+          hasOutput = true
+        }
+
+        try {
+          await axios.get('/crash-and-recovery-A')
+        } catch (e) {
+          return new Promise((resolve, reject) => {
+            setTimeout(() => {
+              if (hasOutput) {
+                reject(new Error('Unexpected output in stdout/stderr after blocking request'))
+              } else {
+                resolve()
+              }
+            }, 50)
+          })
+        }
+
+        assert.fail('Request should have failed')
+      })
+
+      it('should not crash when customer has his own uncaughtException', async () => {
+        let hasOutput = false
+        stdioHandler = () => {
+          hasOutput = true
+        }
+
+        try {
+          await axios.get('/crash-and-recovery-B')
+        } catch (e) {
+          return new Promise((resolve, reject) => {
+            setTimeout(() => {
+              if (hasOutput) {
+                reject(new Error('Unexpected output in stdout/stderr after blocking request'))
+              } else {
+                resolve()
+              }
+            }, 50)
+          })
+        }
+
+        assert.fail('Request should have failed')
+      })
+
+      it('should block manually', async () => {
+        let response
+
+        try {
+          response = await axios.get('/ssrf/http/manual-blocking?host=localhost/ifconfig.pro')
+        } catch (e) {
+          if (!e.response) {
+            throw e
+          }
+          response = e.response
+          assert.strictEqual(response.status, 418)
+          return await assertExploitDetected()
+        }
+
+        assert.fail('Request should have failed')
+      })
+
+      it('should block in a domain', async () => {
+        let response
+
+        try {
+          response = await axios.get('/ssrf/http/should-block-in-domain?host=localhost/ifconfig.pro')
+        } catch (e) {
+          if (!e.response) {
+            throw e
+          }
+          response = e.response
+          assert.strictEqual(response.status, 403)
+          return await assertExploitDetected()
+        }
+
+        assert.fail('Request should have failed')
+      })
+
+      it('should crash as expected after block in domain request', async () => {
+        try {
+          await axios.get('/ssrf/http/should-block-in-domain?host=localhost/ifconfig.pro')
+        } catch (e) {
+          return await testAppCrashesAsExpected()
+        }
+
+        assert.fail('Request should have failed')
+      })
+
+      it('should block when error is unhandled', async () => {
+        try {
+          await axios.get('/ssrf/http/unhandled-error?host=localhost/ifconfig.pro')
+        } catch (e) {
+          if (!e.response) {
+            throw e
+          }
+
+          assert.strictEqual(e.response.status, 403)
+          return await assertExploitDetected()
+        }
+
+        assert.fail('Request should have failed')
+      })
+
+      it('should crash as expected after a requiest block when error is unhandled', async () => {
+        try {
+          await axios.get('/ssrf/http/unhandled-error?host=localhost/ifconfig.pro')
+        } catch (e) {
+          return await testAppCrashesAsExpected()
+        }
+
+        assert.fail('Request should have failed')
+      })
+
+      it('should not execute custom uncaughtExceptionCaptureCallback when it is blocked', async () => {
+        return testCustomErrorHandlerIsNotExecuted('/ssrf/http/custom-uncaught-exception-capture-callback')
+      })
+
+      it('should not execute custom uncaughtException listener', async () => {
+        return testCustomErrorHandlerIsNotExecuted('/ssrf/http/custom-uncaughtException-listener')
+      })
+
+      it('should not crash when app send data after blocking', () => {
+        return testNotCrashedAfterBlocking('/ssrf/http/unhandled-async-write-A')
+      })
+
+      it('should not crash when app stream data after blocking', () => {
+        return testNotCrashedAfterBlocking('/ssrf/http/unhandled-async-write-B')
+      })
+
+      it('should not crash when setHeader, writeHead or end after blocking', () => {
+        return testNotCrashedAfterBlocking('/ssrf/http/unhandled-async-write-C')
+      })
+
+      it('should not crash when appendHeader, flushHeaders, removeHeader after blocking', () => {
+        return testNotCrashedAfterBlocking('/ssrf/http/unhandled-async-write-D')
+      })
+
+      it('should not crash when writeContinue after blocking', () => {
+        return testNotCrashedAfterBlocking('/ssrf/http/unhandled-async-write-E')
+      })
+
+      it('should not crash when writeProcessing after blocking', () => {
+        return testNotCrashedAfterBlocking('/ssrf/http/unhandled-async-write-F')
+      })
+
+      it('should not crash when writeEarlyHints after blocking', () => {
+        return testNotCrashedAfterBlocking('/ssrf/http/unhandled-async-write-G')
+      })
+
+      it('should not crash when res.json after blocking', () => {
+        return testNotCrashedAfterBlocking('/ssrf/http/unhandled-async-write-H')
+      })
+
+      it('should not crash when is blocked using axios', () => {
+        return testNotCrashedAfterBlocking('/ssrf/http/unhandled-axios')
+      })
+
+      it('should not crash when is blocked with unhandled rejection', () => {
+        return testNotCrashedAfterBlocking('/ssrf/http/unhandled-promise')
+      })
+    })
+  })
+
+  describe('--abort-on-uncaught-exception is configured', () => {
+    startServer(true)
+
+    describe('ssrf', () => {
+      it('should not block', async () => {
+        let response
+
+        try {
+          response = await axios.get('/ssrf/http/manual-blocking?host=localhost/ifconfig.pro')
+        } catch (e) {
+          if (!e.response) {
+            throw e
+          }
+          response = e.response
+        }
+
+        // not blocked
+        assert.notEqual(response.status, 418)
+        assert.notEqual(response.status, 403)
+        await assertExploitDetected()
+      })
+    })
+  })
+})