CVE-2025-29476
📋 TL;DR
A buffer overflow vulnerability exists in the compress_chunk_fuzzer component of c-blosc2, a high-performance compression library. This vulnerability could allow attackers to execute arbitrary code or cause denial of service by sending specially crafted input to affected systems. Users of c-blosc2 v2.17.0 and earlier are affected.
💻 Affected Systems
- c-blosc2
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise if the vulnerable component processes attacker-controlled input.
Likely Case
Denial of service through application crashes when processing malformed compression data.
If Mitigated
Limited impact if input validation and memory protections are enabled, potentially causing only crashes.
🎯 Exploit Status
Proof of concept exists in GitHub repository, but weaponization status is unclear.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check GitHub commit after 16450518afddcb3139de627157208e49bfef6987
Vendor Advisory: https://github.com/Blosc/c-blosc2/issues/656
Restart Required: Yes
Instructions:
1. Update to latest c-blosc2 version from GitHub. 2. Recompile applications using c-blosc2. 3. Restart affected services.
🔧 Temporary Workarounds
Input Validation
allImplement strict input validation for compression data before processing
Memory Protection
linuxEnable ASLR and DEP/stack protection on systems
sysctl -w kernel.randomize_va_space=2
🧯 If You Can't Patch
- Isolate systems using c-blosc2 from untrusted networks
- Implement network filtering to block suspicious compression-related traffic
🔍 How to Verify
Check if Vulnerable:
Check c-blosc2 version: if using v2.17.0 or earlier, assume vulnerableCheck Version:
Check library version in code or use package manager: dpkg -l | grep blosc or rpm -qa | grep bloscVerify Fix Applied:
Verify c-blosc2 version is newer than v2.17.0 and commit is after 16450518afddcb3139de627157208e49bfef6987📡 Detection & Monitoring
Log Indicators:
- Application crashes with segmentation faults
- Memory corruption errors in system logs
Network Indicators:
- Unusual compression-related network traffic patterns
SIEM Query:
source="application_logs" AND ("segmentation fault" OR "buffer overflow") AND process="*blosc*"