Advisory Details

June 23rd, 2025

Clam AntiVirus UDF File Parsing Out-Of-Bounds Read Information Disclosure Vulnerability

ZDI-25-417
ZDI-CAN-26010

CVE ID CVE-2025-20234
CVSS SCORE 6.1, AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:L
AFFECTED VENDORS Clam AntiVirus
AFFECTED PRODUCTS Clam AntiVirus
VULNERABILITY DETAILS

This vulnerability allows remote attackers to disclose sensitive information on affected installations of Clam AntiVirus. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within the parsing of file entries within UDF files. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated object. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of the current user.

ADDITIONAL DETAILS Clam AntiVirus has issued an update to correct this vulnerability. More details can be found at:
https://blog.clamav.net/2025/06/clamav-143-and-109-security-patch.html
DISCLOSURE TIMELINE
  • 2025-02-13 - Vulnerability reported to vendor
  • 2025-06-23 - Coordinated public release of advisory
  • 2025-06-23 - Advisory Updated
CREDIT volticks, @movx64 on twitter
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