CVE-2025-62168
📋 TL;DR
Squid caching proxy versions before 7.2 fail to properly redact HTTP authentication credentials in error messages, allowing information disclosure. This vulnerability enables scripts to bypass browser security protections and learn credentials used by trusted clients, potentially exposing security tokens or internal authentication data. Any organization using vulnerable Squid versions for web application load balancing or proxy services is affected.
💻 Affected Systems
- Squid caching proxy
📦 What is this software?
Squid by Squid Cache
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal authentication credentials or security tokens, gaining unauthorized access to backend systems, internal applications, or sensitive data.
Likely Case
Credential leakage leading to unauthorized access to web applications or services behind the Squid proxy.
If Mitigated
Limited information disclosure with minimal impact if proper network segmentation and credential rotation are in place.
🎯 Exploit Status
Exploitation requires triggering error conditions in Squid to leak credentials through error messages.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.2
Vendor Advisory: https://github.com/squid-cache/squid/security/advisories/GHSA-c8cc-phh7-xmxr
Restart Required: Yes
Instructions:
1. Download Squid 7.2 or later from squid-cache.org. 2. Stop Squid service. 3. Install/upgrade to version 7.2+. 4. Restart Squid service.
🔧 Temporary Workarounds
Disable debug information in error emails
allPrevents credential leakage through administrator mailto links by disabling email error data
Add 'email_err_data off' to squid.conf and restart Squid
🧯 If You Can't Patch
- Implement network segmentation to isolate Squid instances from sensitive backend systems
- Rotate all authentication credentials and tokens used by applications behind Squid
🔍 How to Verify
Check if Vulnerable:
Check Squid version with 'squid -v' or 'squid --version' and verify it's below 7.2Check Version:
squid -vVerify Fix Applied:
Confirm version is 7.2 or higher with 'squid -v' and check squid.conf contains 'email_err_data off'📡 Detection & Monitoring
Log Indicators:
- Unusual error messages containing authentication data
- Multiple failed authentication attempts triggering error conditions
Network Indicators:
- Unexpected HTTP error responses containing credential-like strings
- Traffic patterns suggesting credential harvesting
SIEM Query:
source="squid" AND (message="*error*" OR message="*auth*") AND (message="*password*" OR message="*token*" OR message="*credential*")