CVE-2025-25473

What it actually does

The vulnerability is a memory leak in the avformat_free_context function, which fails to properly release allocated memory resources associated with AVFormatContext structures.

Why it matters to the business

Applications using FFmpeg for media processing may experience gradual memory exhaustion, potentially leading to degraded performance or service disruptions over extended operation periods, especially in high-volume environments with many downstream dependents.

How an attack unfolds

An attacker can trigger the memory leak by causing the application to repeatedly allocate and free AVFormatContext objects through crafted media inputs or repeated media handling operations, leading to increased memory consumption without proper reclamation.

How to fix it

Update FFmpeg to the fixed commit c08d300481b8ebb846cd43a473988fdbc6793d1b or later. For GitLab Bitnami, upgrade to version 12.8.1 or newer.

How to confirm the fix worked

Verify the FFmpeg version or commit hash to ensure it includes the fix. Monitor memory usage during context operations to confirm no leaks.

Typical attack path

1. Identify a target application using vulnerable FFmpeg version
2. Craft input that triggers repeated context allocation and freeing
3. Monitor for memory growth in the process
4. Repeat operations to exhaust available resources

How to detect it

Monitor system logs and process memory metrics for unexpected increases during media processing tasks. Check application logs for repeated calls to format context functions.

What your security team should do

• Prioritize updating FFmpeg installations to the patched version
• Review dependent applications for FFmpeg usage and apply fixes promptly
• Implement resource monitoring for early detection of abnormal memory growth