CVE-2021-46250
📋 TL;DR
This vulnerability in ScratchOAuth2 allows attackers to authenticate as other users by exploiting an issue in the SOA2Login::commented function. It affects downstream components that rely on ScratchOAuth2 for authentication. The vulnerability enables complete authentication bypass.
💻 Affected Systems
- ScratchOAuth2
📦 What is this software?
Scratchoauth2 by Scratchoauth2 Project
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain full administrative access to downstream systems, potentially compromising all user accounts and sensitive data.
Likely Case
Attackers impersonate legitimate users to access unauthorized resources, modify data, or perform actions under stolen identities.
If Mitigated
Limited impact with proper network segmentation and monitoring, but authentication bypass remains a critical risk.
🎯 Exploit Status
The vulnerability appears to be an authentication bypass that could be exploited without authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Commit a91879bd58fa83b09283c0708a1864cdf067c64a and later
Vendor Advisory: https://github.com/ScratchVerifier/ScratchOAuth2/commit/a91879bd58fa83b09283c0708a1864cdf067c64a
Restart Required: Yes
Instructions:
1. Update to the latest version of ScratchOAuth2. 2. Replace the vulnerable code with the patched version from commit a91879bd58fa83b09283c0708a1864cdf067c64a. 3. Restart all services using ScratchOAuth2.
🔧 Temporary Workarounds
Disable ScratchOAuth2 Authentication
allTemporarily disable ScratchOAuth2 authentication and use alternative authentication methods.
# Configuration dependent - disable ScratchOAuth2 in your application's auth settings
🧯 If You Can't Patch
- Implement network segmentation to isolate systems using ScratchOAuth2 from critical resources.
- Deploy additional authentication layers (multi-factor authentication) to reduce impact of bypass.
🔍 How to Verify
Check if Vulnerable:
Check if your ScratchOAuth2 version is older than commit a91879bd58fa83b09283c0708a1864cdf067c64a.Check Version:
git log --oneline | head -1Verify Fix Applied:
Verify that the SOA2Login::commented function has been updated to the patched version.📡 Detection & Monitoring
Log Indicators:
- Unexpected authentication successes
- Multiple authentication attempts from same source with different user IDs
- Authentication logs showing user impersonation
Network Indicators:
- Unusual authentication traffic patterns
- Authentication requests bypassing normal flow
SIEM Query:
source="authentication_logs" AND (event="authentication_success" AND user_changed=true) OR (event="user_impersonation")