CVE-2017-15266

What it actually does

A divide-by-zero occurs in EXTRACTOR_wav_extract_method when a WAV file supplies a zero sample rate, causing an immediate crash of the calling process.

Why it matters to the business

Applications that extract metadata from user-supplied audio files can be forced to terminate unexpectedly, interrupting workflows that depend on reliable media processing.

How an attack unfolds

An attacker crafts a minimal WAV file that declares a sample rate of zero, then supplies the file to any program that invokes GNU Libextractor on untrusted input; the library performs an integer division by the sample rate and crashes.

How to fix it

Upgrade GNU Libextractor to a version that validates the sample rate before division; if no patched release is available, wrap calls to the library with input sanitization that rejects zero-rate WAV headers or switch to an alternative metadata extractor.

How to confirm the fix worked

Feed a minimal WAV file with sample rate zero into the updated library and confirm the process no longer terminates; additionally run existing regression tests and fuzzers against the wav_extractor module.

Typical attack path

1. Create a WAV file containing a fmt chunk with sample rate set to zero
2. Deliver the file through email, web upload, or shared storage
3. Victim application calls libextractor to read metadata from the file
4. EXTRACTOR_wav_extract_method divides by the zero sample rate and aborts

How to detect it

Search application and system logs for abrupt termination of processes that link against libextractor while handling .wav files; look for SIGFPE or division-by-zero signals correlated with recent file ingestion.

What your security team should do

• Replace or update GNU Libextractor in all products that parse untrusted media
• Add defensive checks around sample-rate values before any arithmetic
• Restrict metadata extraction to trusted file sources until the component is hardened