CVE-2021-25915
📋 TL;DR
This is a prototype pollution vulnerability in the 'changeset' npm package that allows attackers to modify object prototypes, potentially leading to denial of service or remote code execution. It affects applications using vulnerable versions of the changeset library for data transformation operations. The high CVSS score indicates critical severity with broad impact potential.
💻 Affected Systems
- changeset npm package
📦 What is this software?
Changeset by Changeset Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Denial of service through application crashes or instability, with potential for limited code execution in specific configurations.
If Mitigated
Limited impact with proper input validation and sandboxing, potentially only causing application errors.
🎯 Exploit Status
Prototype pollution vulnerabilities are well-understood and often have public proof-of-concept exploits available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.2.6 and later
Vendor Advisory: https://github.com/eugeneware/changeset/commit/9e588844edbb9993b32e7366cc799262b4447f99
Restart Required: Yes
Instructions:
1. Update package.json to specify changeset version 0.2.6 or higher. 2. Run 'npm update changeset' or 'yarn upgrade changeset'. 3. Restart all affected applications and services.
🔧 Temporary Workarounds
Input Validation and Sanitization
allImplement strict input validation and sanitization for all data processed by changeset functions.
Object.freeze() on Prototypes
allFreeze Object.prototype and other critical prototypes to prevent pollution.
Object.freeze(Object.prototype);
🧯 If You Can't Patch
- Implement network segmentation to isolate affected systems
- Deploy web application firewall with prototype pollution detection rules
🔍 How to Verify
Check if Vulnerable:
Check package.json or run 'npm list changeset' to see if version is between 0.0.1 and 0.2.5 inclusive.Check Version:
npm list changeset | grep changesetVerify Fix Applied:
Verify changeset version is 0.2.6 or higher using 'npm list changeset' and test data transformation functionality.📡 Detection & Monitoring
Log Indicators:
- Unexpected application crashes
- Unusual object property modifications in logs
- Prototype modification warnings
Network Indicators:
- Unusual data patterns in API requests to changeset endpoints
- Malformed JSON payloads with prototype pollution patterns
SIEM Query:
source="application.logs" AND ("prototype pollution" OR "changeset error" OR "unexpected property")🔗 References
- https://github.com/eugeneware/changeset/commit/9e588844edbb9993b32e7366cc799262b4447f99
- https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25915
- https://github.com/eugeneware/changeset/commit/9e588844edbb9993b32e7366cc799262b4447f99
- https://www.whitesourcesoftware.com/vulnerability-database/CVE-2021-25915
