CVE-2019-13220
📋 TL;DR
CVE-2019-13220 is an uninitialized variable vulnerability in stb_vorbis audio decoder that allows attackers to cause denial of service or information disclosure by tricking users into opening malicious Ogg Vorbis files. This affects any application using vulnerable versions of the stb_vorbis library to process audio files. The vulnerability is particularly concerning for media players, games, and applications that handle user-uploaded audio content.
💻 Affected Systems
- stb_vorbis library
- Applications using stb_vorbis (games, media players, audio tools)
📦 What is this software?
Stb Vorbis by Stb Vorbis Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if combined with other vulnerabilities, or sensitive memory disclosure revealing credentials or encryption keys.
Likely Case
Application crash (denial of service) or limited information disclosure from uninitialized stack memory, potentially revealing fragments of sensitive data.
If Mitigated
Application crash with no data loss if proper sandboxing and privilege separation are implemented.
🎯 Exploit Status
Exploitation requires crafting a malicious Ogg Vorbis file and convincing users to open it. The vulnerability is in a widely used library making it attractive to attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in commit 98fdfc6df88b1e34a736d5e126e6c8139c8de1a6 and later
Vendor Advisory: https://github.com/nothings/stb/commit/98fdfc6df88b1e34a736d5e126e6c8139c8de1a6
Restart Required: Yes
Instructions:
1. Update stb_vorbis.c to version after 2019-03-04. 2. Recompile all applications using the library. 3. Restart affected applications/services.
🔧 Temporary Workarounds
Disable Ogg Vorbis file processing
allTemporarily disable or block processing of Ogg Vorbis files in affected applications
Application-specific configuration required
Input validation and sandboxing
linuxImplement strict file validation and run audio processing in isolated containers/sandboxes
docker run --read-only --security-opt=no-new-privileges [container]
firejail --private [application]
🧯 If You Can't Patch
- Implement application whitelisting to prevent execution of untrusted audio processing applications
- Deploy network filtering to block Ogg Vorbis files at perimeter and educate users about file risks
🔍 How to Verify
Check if Vulnerable:
Check if stb_vorbis.c file contains pre-2019-03-04 code or grep for 'start_decoder' function without proper initializationCheck Version:
grep -n 'stb_vorbis_version' stb_vorbis.c || check file modification dateVerify Fix Applied:
Verify stb_vorbis.c includes commit 98fdfc6df88b1e34a736d5e126e6c8139c8de1a6 changes📡 Detection & Monitoring
Log Indicators:
- Application crashes with memory access violations
- Unexpected file processing errors for .ogg files
Network Indicators:
- Unusual .ogg file downloads from untrusted sources
- Multiple failed file processing attempts
SIEM Query:
source="application.log" ("segmentation fault" OR "access violation") AND "*.ogg"🔗 References
- http://nothings.org/stb_vorbis/
- https://github.com/nothings/stb/commit/98fdfc6df88b1e34a736d5e126e6c8139c8de1a6
- https://github.com/nothings/stb/commits/master/stb_vorbis.c
- https://lists.debian.org/debian-lts-announce/2023/01/msg00045.html
- http://nothings.org/stb_vorbis/
- https://github.com/nothings/stb/commit/98fdfc6df88b1e34a736d5e126e6c8139c8de1a6
- https://github.com/nothings/stb/commits/master/stb_vorbis.c
- https://lists.debian.org/debian-lts-announce/2023/01/msg00045.html
