Critical severity · published May 28, 2021
CVE-2021-32647
Post-authentication Remote Code Execution (RCE) in emissary:emissary
9.1
CVSS
2.8%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)2.8% · higher than 87% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EM
emissary · NationalSecurityAgency
= 6.4.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-32647
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-32647
Exploit
https://github.com/NationalSecurityAgency/emissary/blob/30c54ef16c6eb6ed09604a929939fb9f66868382/src/main/java/emissary/server/mvc/internal/CreatePlaceAction.java#L36
Patch
https://github.com/NationalSecurityAgency/emissary/security/advisories/GHSA-ph73-7v9r-wg32
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