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CVE-2024-36486NVD status: Analyzed

Parallels Desktop for Mac: Improper Link Resolution Before File Access

CVE-2024-36486 is a high-severity improper link resolution before file access vulnerability in Parallels Desktop for Mac from Parallels, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected Parallels Desktop for Mac versions: version 20.1.1 (55740). The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.34% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of Parallels Desktop for Mac you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
ParallelsParallels Desktop for Macversion 20.1.1 (55740)Not stated
ParallelsParallels Desktop20.1.1_\(55740\)Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cisco.com).

Official description

A privilege escalation vulnerability exists in the virtual machine archive restoration functionality of Parallels Desktop for Mac version 20.1.1 (55740). When an archived virtual machine is restored, the prl_vmarchiver tool decompresses the file and writes the content back to its original location using root privileges. An attacker can exploit this process by using a hard link to write to an arbitrary file, potentially resulting in privilege escalation.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Link Resolution Before File Access

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

How developers prevent this class of flaw

  • Follow the principle of least privilege when assigning access rights to entities in a software system. Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

More Improper Link Resolution Before File Access vulnerabilities (CWE-59)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Technical write-ups (may include proof of concept)

Other vulnerabilities in Parallels Desktop for Mac

All Parallels Desktop for Mac vulnerabilities

Recent Improper Link Resolution Before File Access vulnerabilities

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