CVE-2021-32647
Affected versions of Emissary are vulnerable to post-authentication Remote Code Execution (RCE).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.85%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Emissary is a P2P based data-driven workflow engine. Affected versions of Emissary are vulnerable to post-authentication Remote Code Execution (RCE). The [`CreatePlace`](https://github.com/NationalSecurityAgency/emissary/blob/30c54ef16c6eb6ed09604a929939fb9f66868382/src/main/java/emissary/server/mvc/internal/CreatePlaceAction.java#L36) REST endpoint accepts an `sppClassName` parameter which is used to load an arbitrary class. This class is later instantiated using a constructor with the following signature: `<constructor>(String, String, String)`. An attacker may find a gadget (class) in the application classpath that could be used to achieve Remote Code Execution (RCE) or disrupt the application. Even though the chances to find a gadget (class) that allow arbitrary code execution are low, an attacker can still find gadgets that could potentially crash the application or leak sensitive data. As a work around disable network access to Emissary from untrusted sources.
- CVSS 3.1
- 9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 2.85% probability · 86th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-74, CWE-470
- Affected
- nsa/emissary
- Source
- security-advisories@github.com
References
- https://github.com/NationalSecurityAgency/emissary/blob/30c54ef16c6eb6ed09604a929939fb9f66868382/src/main/java/emissary/server/mvc/internal/CreatePlaceAction.java#L36Exploit, Third Party Advisory
- https://github.com/NationalSecurityAgency/emissary/security/advisories/GHSA-ph73-7v9r-wg32Patch, Third Party Advisory
- https://github.com/NationalSecurityAgency/emissary/blob/30c54ef16c6eb6ed09604a929939fb9f66868382/src/main/java/emissary/server/mvc/internal/CreatePlaceAction.java#L36Exploit, Third Party Advisory
- https://github.com/NationalSecurityAgency/emissary/security/advisories/GHSA-ph73-7v9r-wg32Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.