CVE-2021-32685
📋 TL;DR
This vulnerability in tEnvoy's NaCl signature verification allows attackers to forge signatures by providing any invalid signature that matches the SHA-512 hash of the message. The verifyWithMessage method incorrectly returns true for these forged signatures, compromising cryptographic integrity. This affects any system using tEnvoy versions before 7.0.3 for signature verification.
💻 Affected Systems
- tEnvoy
📦 What is this software?
Tenvoy by Togatech
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of cryptographic integrity allowing attackers to forge signed messages, impersonate legitimate users, bypass authentication, and potentially execute unauthorized actions.
Likely Case
Signature forgery enabling data tampering, authentication bypass, and unauthorized access to protected systems or data.
If Mitigated
Limited impact with proper network segmentation and additional authentication layers, though cryptographic guarantees remain broken.
🎯 Exploit Status
Exploitation requires generating SHA-512 hash collisions, which is computationally feasible for attackers. No authentication needed to exploit the vulnerable method.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.0.3
Vendor Advisory: https://github.com/TogaTech/tEnvoy/security/advisories/GHSA-7r96-8g3x-g36m
Restart Required: Yes
Instructions:
1. Update tEnvoy to version 7.0.3 or later. 2. Replace all instances of tEnvoy in package.json with ^7.0.3. 3. Run npm update tEnvoy. 4. Restart all applications using tEnvoy.
🔧 Temporary Workarounds
Manual code patch
allModify the verifyWithMessage method to properly call this.verify with .verified property
Edit tenvoy.js, locate tEnvoyNaClSigningKey class, find verifyWithMessage method, change return statement to: return this.verify(signature, message).verified;
🧯 If You Can't Patch
- Implement additional signature verification using alternative cryptographic libraries
- Disable or restrict access to systems using tEnvoy signature verification until patched
🔍 How to Verify
Check if Vulnerable:
Check if tEnvoy version is below 7.0.3 in package.json or via npm list tEnvoyCheck Version:
npm list tEnvoy | grep tEnvoyVerify Fix Applied:
Verify tEnvoy version is 7.0.3 or higher and test signature verification with known invalid signatures📡 Detection & Monitoring
Log Indicators:
- Failed signature verification attempts returning success
- Unexpected successful signature validations
Network Indicators:
- Unusual patterns in signed message traffic
- Messages with valid signatures from unexpected sources
SIEM Query:
application_logs WHERE message CONTAINS 'signature verification' AND result = 'success' AND source_ip NOT IN (trusted_ips)🔗 References
- https://github.com/TogaTech/tEnvoy/commit/a121b34a45e289d775c62e58841522891dee686b
- https://github.com/TogaTech/tEnvoy/releases/tag/v7.0.3
- https://github.com/TogaTech/tEnvoy/security/advisories/GHSA-7r96-8g3x-g36m
- https://github.com/TogaTech/tEnvoy/commit/a121b34a45e289d775c62e58841522891dee686b
- https://github.com/TogaTech/tEnvoy/releases/tag/v7.0.3
- https://github.com/TogaTech/tEnvoy/security/advisories/GHSA-7r96-8g3x-g36m
