SixLabors ImageSharp has Excessive Memory Allocation in Gif Decoder

Impact

What kind of vulnerability is it? Who is impacted?

A vulnerability discovered in the ImageSharp library, where the processing of specially crafted files can lead to excessive memory usage in the Gif decoder. The vulnerability is triggered when ImageSharp attempts to process image files that are designed to exploit this flaw.

Patches

Has the problem been patched? What versions should users upgrade to?

The problem has been patched. All users are advised to upgrade to v3.1.5 or v2.1.9.

Workarounds

Is there a way for users to fix or remediate the vulnerability without upgrading?

Before calling Image.Decode(Async), use Image.Identify to determine the image dimensions in order to enforce a limit.

References

Are there any links users can visit to find out more?

• https://github.com/SixLabors/ImageSharp/pull/2759
• https://github.com/SixLabors/ImageSharp/pull/2764
• https://github.com/SixLabors/ImageSharp/pull/2770
• ImageSharp: Security Considerations
• ImageSharp.Web: Securing Processing Commands