CyberSecBulletin
CVE-2024-7231NVD status: Analyzed

Cleanup Premium: Improper Link Resolution Before File Access

CVE-2024-7231 is a high-severity improper link resolution before file access vulnerability in Cleanup Premium from Avast, 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 Cleanup Premium versions: 23.4 (build 15592). 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 Cleanup Premium you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
AvastCleanup Premium23.4 (build 15592)Not stated
Avastcleanup23.4Not 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 NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighNVD
CVSS 3.07.8HighCNA (trendmicro.com)

Official description

Avast Cleanup Premium Link Following Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Avast Cleanup Premium. 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 Avast Cleanup Service. By creating a symbolic link, an attacker can abuse the service to delete a file. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of SYSTEM. Was ZDI-CAN-22894.

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 Cleanup Premium

All Cleanup Premium vulnerabilities

Recent Improper Link Resolution Before File Access vulnerabilities

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