// For flags

CVE-2021-34986

Parallels Desktop Service Time-Of-Check Time-Of-Use Privilege Escalation Vulnerability

Severity Score

7.8
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop 16.5.0 (49183). An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the Parallels Service. By creating a symbolic link, an attacker can abuse the service to execute a file. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root. Was ZDI-CAN-13932.

Esta vulnerabilidad permite a atacantes locales escalar privilegios en las instalaciones afectadas de Parallels Desktop versión 16.5.0 (49183). Un atacante debe obtener primero la capacidad de ejecutar código poco privilegiado en el sistema de destino para poder explotar esta vulnerabilidad. El fallo específico se presenta dentro del Servicio Parallels. Al crear un enlace simbólico, un atacante puede abusar del servicio para ejecutar un archivo. Un atacante puede aprovechar esta vulnerabilidad para escalar privilegios y ejecutar código arbitrario en el contexto de root. Era ZDI-CAN-13932

This vulnerability allows local attackers to escalate privileges on affected installations of Parallels Desktop. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
The specific flaw exists within the Parallels Service. By creating a symbolic link, an attacker can abuse the service to execute a file. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root.

*Credits: say2
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-06-17 CVE Reserved
  • 2022-02-18 CVE Published
  • 2023-03-08 EPSS Updated
  • 2024-08-04 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition
CAPEC
References (2)
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Parallels
Search vendor "Parallels"
Parallels Desktop
Search vendor "Parallels" for product "Parallels Desktop"
16.5.0
Search vendor "Parallels" for product "Parallels Desktop" and version "16.5.0"
macos
Affected