CVE-2021-42835
Plex Media Server Remote Code Execution via RPC TOCTOU Race Condition
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).
INFO
Published Date :
Dec. 8, 2021, 3:15 p.m.
Last Modified :
Nov. 21, 2024, 6:28 a.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2021-42835
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 2.0 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
CVE-2021-42835 vulnerability.
Public PoC/Exploit Available at Github
CVE-2021-42835 has a 6 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-42835.
| URL | Resource |
|---|---|
| https://bugsec.com/experts_teams/ | Third Party Advisory |
| https://forums.plex.tv/t/security-regarding-cve-2021-42835/761510 | Vendor 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-2021-42835/761510 | Vendor 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 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-42835 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-42835
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
All CVE - PoC in GitHub
poc proofofconcept tester allcve cvegithub cvenew cvepoc cveupdate
None
None
None
None
Python C++ C
Plex media server local privilige escalation poc - CVE-2021-42835
C++ C
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-42835 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-42835 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://bugsec.com/experts_teams/ Added Reference https://forums.plex.tv/t/security-regarding-cve-2021-42835/761510 Added Reference https://ir-on.io/2021/12/02/local-privilege-plexcalation/ Added Reference https://www.plex.tv/media-server-downloads/ -
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Initial Analysis by [email protected]
Dec. 13, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:L/AC:M/Au:N/C:C/I:C/A:C) Added CVSS V3.1 NIST AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Changed Reference Type https://bugsec.com/experts_teams/ No Types Assigned https://bugsec.com/experts_teams/ Third Party Advisory Changed Reference Type https://forums.plex.tv/t/security-regarding-cve-2021-42835/761510 No Types Assigned https://forums.plex.tv/t/security-regarding-cve-2021-42835/761510 Vendor Advisory Changed Reference Type https://ir-on.io/2021/12/02/local-privilege-plexcalation/ No Types Assigned https://ir-on.io/2021/12/02/local-privilege-plexcalation/ Exploit, Third Party Advisory Changed Reference Type https://www.plex.tv/media-server-downloads/ No Types Assigned https://www.plex.tv/media-server-downloads/ Product, Vendor Advisory Added CWE NIST CWE-367 Added CPE Configuration AND OR *cpe:2.3:a:plex:media_server:*:*:*:*:*:*:*:* versions up to (excluding) 1.25.0.5282 OR cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*
Vulnerability Scoring Details
Base CVSS Score: 7
Base CVSS Score: 6.9
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
16.91 }} 1.86%
score
0.94678
percentile