CVE-2024-20696

What it actually does

The vulnerability permits arbitrary code execution when libarchive processes a specially crafted archive file on affected Windows systems, triggered locally with user interaction and low privileges.

Why it matters to the business

Attackers could gain full control over affected systems, leading to data theft, ransomware deployment, or lateral movement, especially in environments relying on archive handling for backups or file transfers; high prevalence across Windows deployments increases exposure risk despite low EPSS.

How an attack unfolds

An attacker crafts a malicious archive exploiting parsing flaws in libarchive, delivers it via email or download, and relies on the victim opening or extracting it on a vulnerable Windows system to achieve code execution.

How to fix it

Apply the latest Windows security updates addressing libarchive components; where updates are unavailable, restrict archive handling to trusted sources and consider sandboxing extraction processes.

How to confirm the fix worked

Verify patch installation via Windows Update history or system version checks; test by attempting extraction of known benign archives and monitoring for anomalous behavior in libarchive libraries.

Typical attack path

1. Identify or create a target using archive extraction features on Windows
2. Craft a malicious archive file exploiting libarchive parsing logic
3. Deliver the file through phishing, shared storage, or web download
4. Trick the user into opening or extracting the archive
5. Achieve remote code execution with the privileges of the extracting process

How to detect it

Review system logs for unusual process spawns or crashes during archive operations; inspect file access logs for suspicious archive files from external sources.

What your security team should do

• Prioritize deployment of available Windows updates to all affected versions
• Monitor for new fixed versions from Microsoft and test in staging environments
• Implement application allowlisting to limit execution of archive tools
• Educate users on risks of opening untrusted archive files