CVE-2021-42835

Severity Score

7.0

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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).

Se ha detectado un problema en Plex Media Server versiones hasta 1.24.4.5081-e362dc1ee. Un atacante (con un punto de apoyo en un extremo por medio de una cuenta de usuario con pocos privilegios) puede acceder al servicio RPC expuesto del componente de servicio de actualización. Esta funcionalidad RPC permite al atacante interactuar con la funcionalidad RPC y ejecutar código desde una ruta de su elección (local, o remota por SMB) debido a una condición de carrera TOCTOU. Esta ejecución de código es producida en el contexto del servicio de actualización de Plex (que es ejecutado como SYSTEM)

*Credits: N/A

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Local

Attack Complexity

Medium

Authentication

None

Confidentiality

Complete

Integrity

Complete

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-10-22 CVE Reserved
2021-12-08 CVE Published
2024-03-01 EPSS Updated
2024-08-04 CVE Updated
2024-08-04 First Exploit
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition

CAPEC

References (4)

URL	Tag	Source
https://bugsec.com/experts_teams	Third Party Advisory

URL	Date	SRC
https://ir-on.io/2021/12/02/local-privilege-plexcalation	2024-08-04

URL	Date	SRC

URL	Date	SRC
https://forums.plex.tv/t/security-regarding-cve-2021-42835/761510	2021-12-13
https://www.plex.tv/media-server-downloads	2021-12-13

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Plex Search vendor "Plex"	Media Server Search vendor "Plex" for product "Media Server"	< 1.25.0.5282 Search vendor "Plex" for product "Media Server" and version " < 1.25.0.5282"	-	Affected	in	Microsoft Search vendor "Microsoft"	Windows Search vendor "Microsoft" for product "Windows"	-	-	Safe