Description

Canimaan Software ClamXAV versions 3.3 - 3.11 contains a local privilege escalation vulnerability in the Privileged Helper Tool caused by a race condition and insufficient file validation, allowing a local attacker to execute arbitrary code with system privileges. Fixed in 3.11.1.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.0",
  "pubDate": "2026-10-05T21:16:36.093Z",
  "pubdate": "2026-10-05T21:16:36.093Z",
  "executiveSummary": "Canimaan Software ClamXAV versions 3.3 through 3.11 are affected by a Local Privilege Escalation (LPE) vulnerability residing within the application's Privileged Helper Tool.\nThe vulnerability is characterized by a race condition coupled with insufficient file validation mechanisms, which permits a local, unprivileged attacker to manipulate the helper tool's operation.\nSuccessful exploitation allows an adversary to execute arbitrary code with system-level privileges on the host macOS system.\nThe risk is categorized as high, as it grants complete control over the affected system to an attacker who already possesses local access.\nThe flaw does not require remote network connectivity, as the attack vector is strictly local; however, it bypasses standard operating system security boundaries by leveraging the trust inherently granted to the Privileged Helper Tool.\nThis vulnerability is remediated in version 3.11.1.",
  "technicalDetails": "The vulnerability exists within the ClamXAV Privileged Helper Tool, a background daemon designed to perform administrative tasks that require elevated system privileges. The root cause of this security defect is a race condition, specifically a Time-of-Check to Time-of-Use (TOCTOU) vulnerability, exacerbated by inadequate file path validation and integrity checking.\nIn the context of the Privileged Helper Tool, the application fails to adequately secure the transition between verifying the metadata or location of a target file and the subsequent execution or processing of that file. By timing an attack to occur during this execution window, a local actor can swap a legitimate file or symbolic link with a malicious payload.\nThe exploitation flow typically begins with an attacker identifying a file path handled by the Privileged Helper Tool. Due to the insufficient validation, the tool may process a location that is writable by a low-privileged user. By creating a race condition, the attacker forces the helper tool to perform operations on a file manipulated by the attacker rather than the expected system file.\nBecause the helper tool operates with system privileges (root), the attacker's supplied payload is executed in the same security context. This effectively escapes the constraints of the sandboxed or standard user environment.\nThe technical requirements for this exploit include local access to the system. Since the helper tool is a privileged component, the attacker does not need to bypass initial authentication to trigger the vulnerability, as they are interfacing with the interface provided by the helper tool itself. The post-exploitation impact is total system compromise, including the ability to install persistent backdoors, access sensitive user data, or modify system files.\nAffected versions are limited to ClamXAV 3.3 up to 3.11. The flaw resides in the handling of privileged IPC (Inter-Process Communication) and file system operations within the helper tool architecture. The failure to implement atomic file operations or utilize secure path resolution allows the adversary to achieve code execution."
}