CVE-2015-6673

What it actually does

Use-after-free in Decoder.cpp of libpgf allows memory to be referenced after deallocation during image decoding, enabling memory corruption that can lead to arbitrary code execution or crashes.

Why it matters to the business

Applications relying on libpgf for PGF image handling become vulnerable to remote code execution or denial of service, potentially compromising systems that process untrusted graphics files and increasing risk in image-heavy workflows.

How an attack unfolds

An attacker creates a malformed PGF image file that triggers the use-after-free during decoding; when a vulnerable application processes the file, the freed memory is reused to inject and execute attacker-controlled code.

How to fix it

Upgrade libpgf to version 6.15.32 or later; rebuild and redeploy any dependent applications with the patched library.

How to confirm the fix worked

Confirm libpgf version is 6.15.32 or higher via package manager or build logs; test decoding of known-good and edge-case PGF files for stability.

Typical attack path

1. Craft a malicious PGF image exploiting the Decoder.cpp flaw
2. Deliver the image via network, email, or file share to a target application
3. Trigger image decoding in the vulnerable libpgf library
4. Leverage the resulting memory corruption for code execution or crash

How to detect it

Monitor application logs and crash reports for memory access violations or segmentation faults during PGF decoding; review process dumps for signs of memory reuse anomalies in image-handling code paths.

What your security team should do

• Prioritize updating libpgf across all affected systems due to remote code execution potential
• Inventory applications and dependencies using libpgf
• Implement network segmentation or input sanitization for untrusted PGF files until patched