CVE-2020-24074
📋 TL;DR
CVE-2020-24074 is a critical buffer overflow vulnerability in the silk-v3-decoder program's decode function, which fails to properly validate input data. This allows attackers to execute arbitrary code or cause denial of service by providing specially crafted Silk audio files. Anyone using the affected silk-v3-decoder version is vulnerable.
💻 Affected Systems
- silk-v3-decoder
📦 What is this software?
Silk V3 Decoder by Silk V3 Decoder Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with full system compromise, allowing attackers to install malware, exfiltrate data, or pivot to other systems.
Likely Case
Denial of service through program crashes or potential remote code execution in systems processing untrusted Silk audio files.
If Mitigated
Limited impact if proper input validation and sandboxing are implemented, potentially reduced to denial of service only.
🎯 Exploit Status
The vulnerability is in a widely used audio decoder, making exploitation straightforward with crafted audio files. Public GitHub issues demonstrate the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Fixed in commit d216599502662db01c07cc0dfd95ff1f1eaaea02 and later versions
Vendor Advisory: https://github.com/kn007/silk-v3-decoder/commit/d216599502662db01c07cc0dfd95ff1f1eaaea02
Restart Required: No
Instructions:
1. Update silk-v3-decoder to the latest version from GitHub. 2. Replace the existing decode binary with the patched version. 3. Recompile any applications using the library if necessary.
🔧 Temporary Workarounds
Input Validation Wrapper
allCreate a wrapper script that validates Silk audio files before passing to decode program
#!/bin/bash
# Validate file size and basic structure before decoding
if [ -f "$1" ]; then
# Add validation logic here
./decode "$1"
fi
Sandbox Execution
linuxRun decode program in a sandboxed environment with limited privileges
firejail --net=none --private ./decode input.silk
bwrap --unshare-all --ro-bind / / --dev /dev --proc /proc ./decode input.silk
🧯 If You Can't Patch
- Disable or remove silk-v3-decoder from production systems
- Implement strict network controls to prevent processing of untrusted Silk audio files
🔍 How to Verify
Check if Vulnerable:
Check if decode binary exists and its version: strings decode | grep -i 'silk.*decoder' or check commit hash if built from sourceCheck Version:
./decode --version 2>&1 | head -5 or check build date in binary metadataVerify Fix Applied:
Verify the decode program includes the fix by checking for commit d216599502662db01c07cc0dfd95ff1f1eaaea02 in version information📡 Detection & Monitoring
Log Indicators:
- Segmentation fault or abnormal termination of decode process
- Unusual memory consumption patterns in decode process
- Multiple failed decode attempts with similar file patterns
Network Indicators:
- Unexpected network connections originating from decode process
- Large volume of Silk audio file uploads to vulnerable endpoints
SIEM Query:
process_name:"decode" AND (event_type:"crash" OR memory_usage:>threshold)