CyberSecBulletin
CVE-2023-50226NVD status: Analyzed

Desktop: Improper Link Resolution Before File Access

CVE-2023-50226 is a high-severity improper link resolution before file access vulnerability in Desktop from Parallels, with a CVSS 3.0 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 Desktop versions: 18.3.0 (53606). The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.69% chance of exploitation within 30 days, higher than 53% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update parallels_desktop to 18.3.2 or a later version.
  2. Read the advisory on kb.parallels.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
ParallelsDesktop18.3.0 (53606)Not stated
Parallelsparallels_desktopbefore 18.3.218.3.2

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:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (trendmicro.com).

Official description

Parallels Desktop Updater Link Following Local Privilege Escalation Vulnerability. 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 host system in order to exploit this vulnerability. The specific flaw exists within the Updater service. By creating a symbolic link, an attacker can abuse the service to move arbitrary files. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root. . Was ZDI-CAN-21227.

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: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in Desktop

All Desktop vulnerabilities

Recent Improper Link Resolution Before File Access vulnerabilities

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