CVE-2024-22957

What it actually does

Out-of-bounds read in dict_do_lookup allows an attacker-controlled SWF structure to access memory beyond allocated dictionary bounds, resulting in a process crash (denial of service).

Why it matters to the business

Processing untrusted SWF files with affected swftools versions can cause the utility to terminate unexpectedly, disrupting automated media conversion or analysis workflows that depend on the tool.

How an attack unfolds

An attacker crafts a malicious SWF file containing a specially formed dictionary that triggers the out-of-bounds read inside dict_do_lookup when the file is opened by any swftools component; the resulting crash produces a denial-of-service condition without requiring elevated privileges.

How to fix it

Upgrade to a patched release of swftools once available; until then, avoid processing untrusted SWF files with any swftools utilities and consider sandboxing or replacing the tool in automated pipelines.

How to confirm the fix worked

Confirm the installed swftools version is newer than 0.9.2 and test that the dict_do_lookup function no longer crashes on the original proof-of-concept SWF file.

Typical attack path

1. Craft a malformed SWF file that exercises the vulnerable dictionary lookup path
2. Deliver the file to a system running swftools (local file, email attachment, or web download)
3. Invoke any swftools binary (e.g., swfextract, swfdump) on the file
4. Trigger the out-of-bounds read and observe process termination

How to detect it

Search application or system logs for unexpected termination of swftools binaries immediately after opening SWF files; look for segmentation faults or access-violation events correlated with SWF processing.

What your security team should do

• Inventory all systems and build pipelines that invoke swftools
• Block untrusted SWF files from reaching any swftools instance until a fixed build is deployed
• Monitor for new upstream releases and apply the update as soon as it is published