CVE-2021-42835
An attacker (with a foothold in a endpoint via a low-privileged user account) can access the exposed RPC service of the update service component.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.18%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
An issue was discovered in Plex Media Server through 1.24.4.5081-e362dc1ee. An attacker (with a foothold in a endpoint via a low-privileged user account) can access the exposed RPC service of the update service component. This RPC functionality allows the attacker to interact with the RPC functionality and execute code from a path of his choice (local, or remote via SMB) because of a TOCTOU race condition. This code execution is in the context of the Plex update service (which runs as SYSTEM).
- CVSS 3.1
- 7.0 HIGHCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 1.18% probability · 66th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-367
- Affected
- plex/media server
- Source
- cve@mitre.org
References
- https://bugsec.com/experts_teams/Third Party Advisory
- https://forums.plex.tv/t/security-regarding-cve-2021-42835/761510Vendor Advisory
- https://ir-on.io/2021/12/02/local-privilege-plexcalation/Exploit, Third Party Advisory
- https://www.plex.tv/media-server-downloads/Product, Vendor Advisory
- https://bugsec.com/experts_teams/Third Party Advisory
- https://forums.plex.tv/t/security-regarding-cve-2021-42835/761510Vendor Advisory
- https://ir-on.io/2021/12/02/local-privilege-plexcalation/Exploit, Third Party Advisory
- https://www.plex.tv/media-server-downloads/Product, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.