CVE-2021-42835 Race condition in n/a
A TOCTOU race condition in the update service allows low-privileged attackers to execute arbitrary code as SYSTEM via RPC.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-42835?
CVE-2021-42835 is a high-severity vulnerability in n/a, published on 8 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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).
Weakness: CWE-367
Which versions are affected by CVE-2021-42835?
It affects 1 product.
Products include Plex Media Server.
How do I fix CVE-2021-42835?
No fix has been published for CVE-2021-42835 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-42835 being exploited?
There is no known exploitation of CVE-2021-42835 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in n/a
- CVE-2026-96656 Plex Media Server External Control of File Name or Path
- CVE-2020-5741 Plex Media Server Remote Code Execution
- CVE-2026-96654 Plex Media Server Improper Neutralization of Encoded URI Schemes in a Web Page
- CVE-2026-96652 Plex Media Server Server-Side Request Forgery (SSRF)
- CVE-2026-96655 Plex Media Server Server-Side Request Forgery (SSRF)
Sources
Also known as GHSA-724p-rm8h-wjx7.