CVE-2022-21190
This is a bypass of [CVE-2022-22143](https://security.snyk.io/vuln/SNYK-JS-CONVICT-2340604).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (3.91%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
This affects the package convict before 6.2.3. This is a bypass of [CVE-2022-22143](https://security.snyk.io/vuln/SNYK-JS-CONVICT-2340604). The [fix](https://github.com/mozilla/node-convict/commit/3b86be087d8f14681a9c889d45da7fe3ad9cd880) introduced, relies on the startsWith method and does not prevent the vulnerability: before splitting the path, it checks if it starts with __proto__ or this.constructor.prototype. To bypass this check it's possible to prepend the dangerous paths with any string value followed by a dot, like for example foo.__proto__ or foo.this.constructor.prototype.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 3.91% probability · 90th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-1321
- Affected
- mozilla/convict
- Source
- report@snyk.io
References
- https://gist.github.com/dellalibera/cebce20e51410acebff1f46afdc89808Exploit, Third Party Advisory
- https://github.com/mozilla/node-convict/blob/3b86be087d8f14681a9c889d45da7fe3ad9cd880/packages/convict/src/main.js%23L571Broken Link, Patch, Third Party Advisory
- https://github.com/mozilla/node-convict/blob/master/CHANGELOG.md%23623---2022-05-07Broken Link, Release Notes, Tool Signature
- https://github.com/mozilla/node-convict/commit/1ea0ab19c5208f66509e1c43b0d0f21c1fd29b75Patch, Tool Signature
- https://snyk.io/vuln/SNYK-JS-CONVICT-2774757Exploit, Third Party Advisory
- https://gist.github.com/dellalibera/cebce20e51410acebff1f46afdc89808Exploit, Third Party Advisory
- https://github.com/mozilla/node-convict/blob/3b86be087d8f14681a9c889d45da7fe3ad9cd880/packages/convict/src/main.js%23L571Broken Link, Patch, Third Party Advisory
- https://github.com/mozilla/node-convict/blob/master/CHANGELOG.md%23623---2022-05-07Broken Link, Release Notes, Tool Signature
- https://github.com/mozilla/node-convict/commit/1ea0ab19c5208f66509e1c43b0d0f21c1fd29b75Patch, Tool Signature
- https://snyk.io/vuln/SNYK-JS-CONVICT-2774757Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.