CVE-2021-42835

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).

• CWE-367

• 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

Published

Dec 8, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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