CVE-2021-39131
📋 TL;DR
CVE-2021-39131 is a denial-of-service vulnerability in the ced Node.js library that causes process crashes when non-Buffer data types are passed to its character encoding detection function. This affects applications using ced v0.1.0 for character encoding detection. The vulnerability can be exploited to crash Node.js processes, disrupting service availability.
💻 Affected Systems
- ced (Node.js character encoding detection library)
📦 What is this software?
Ced by Ced Project
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service causing application downtime and service disruption
Likely Case
Application crashes leading to service interruptions and potential data loss in active sessions
If Mitigated
No impact if proper input validation or patched version is used
🎯 Exploit Status
Exploitation is straightforward - simply passing non-Buffer data to affected functions causes crash
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: ced v1.0.0
Vendor Advisory: https://github.com/sonicdoe/ced/security/advisories/GHSA-27wq-qx3q-fxm9
Restart Required: Yes
Instructions:
1. Update package.json to require ced version 1.0.0 or higher. 2. Run 'npm update ced' or 'yarn upgrade ced'. 3. Restart all Node.js processes using the ced library.
🔧 Temporary Workarounds
Input validation workaround
allValidate all inputs to ced functions to ensure they are Buffer objects before processing
// Before calling ced functions, add: if (!Buffer.isBuffer(input)) { throw new Error('Input must be Buffer'); }
🧯 If You Can't Patch
- Implement strict input validation using Buffer.isBuffer() before passing data to ced functions
- Isolate ced usage to specific modules with input sanitization and implement circuit breakers
🔍 How to Verify
Check if Vulnerable:
Check package.json or node_modules for ced version 0.1.0Check Version:
npm list ced | grep ced or check package.json for ced versionVerify Fix Applied:
Verify ced version is 1.0.0 or higher in package.json and node_modules📡 Detection & Monitoring
Log Indicators:
- Node.js process crashes with segmentation faults
- Application restarts without clear errors
- Error logs showing process termination
Network Indicators:
- Sudden service unavailability
- Connection resets from affected services
SIEM Query:
process.name:node AND (event.type:crash OR exit_code:139 OR exit_code:134)🔗 References
- https://github.com/sonicdoe/ced/commit/a4d9f10b6bf1cd468d1a5b9a283cdf437f8bb7b3
- https://github.com/sonicdoe/ced/releases/tag/v1.0.0
- https://github.com/sonicdoe/ced/security/advisories/GHSA-27wq-qx3q-fxm9
- https://github.com/sonicdoe/ced/commit/a4d9f10b6bf1cd468d1a5b9a283cdf437f8bb7b3
- https://github.com/sonicdoe/ced/releases/tag/v1.0.0
- https://github.com/sonicdoe/ced/security/advisories/GHSA-27wq-qx3q-fxm9
