CVE-2021-45260

What it actually does

Null pointer dereference in lsr_read_id.part triggers segmentation fault and immediate process termination when parsing specially crafted input.

Why it matters to the business

Media processing or playback applications using gpac become unavailable after handling a single malicious file, interrupting workflows that depend on reliable local file handling.

How an attack unfolds

An attacker crafts a file that reaches the vulnerable lsr_read_id.part code path; the file is opened locally by a user or automated process, causing the application to crash with no further attacker interaction required.

How to fix it

Upgrade gpac to a version that resolves the null pointer dereference in lsr_read_id.part; if no patched release is available, replace gpac with an unaffected media library or sandbox all invocations of gpac to limit crash impact.

How to confirm the fix worked

Reproduce the crash with a known triggering file before and after the upgrade; confirm the process no longer terminates and that normal media files continue to process without error.

Typical attack path

1. Generate or obtain a file that triggers the null dereference in lsr_read_id.part
2. Deliver the file via email, download link, or shared storage
3. Victim or automated job opens the file with gpac or a dependent application
4. Application crashes due to segmentation fault

How to detect it

Review system and application logs for segmentation fault entries or core dumps containing references to lsr_read_id.part; correlate with gpac process terminations on hosts that process untrusted media files.

• lsr_read_id.part
• segmentation fault.*gpac
• gpac.*core dumped

What your security team should do

• Inventory all systems and containers that invoke gpac for media processing
• Block or filter untrusted files from reaching gpac until patched
• Monitor crash logs for segmentation faults originating from lsr_read_id.part
• Plan migration or upgrade within the next maintenance window