CVE-2025-62168

Squid is a caching proxy for the Web. In Squid versions prior to 7.2, a failure to redact HTTP authentication credentials in error handling allows information disclosure. The vulnerability allows a script to bypass browser security protections and learn the credentials a trusted client uses to authenticate. This potentially allows a remote client to identify security tokens or credentials used internally by a web application using Squid for backend load balancing. These attacks do not require Squid to be configured with HTTP authentication. The vulnerability is fixed in version 7.2. As a workaround, disable debug information in administrator mailto links generated by Squid by configuring squid.conf with email_err_data off.

Weakness

The product generates an error message that includes sensitive information about its environment, users, or associated data.

Affected Software

Potential Mitigations

• Ensure that error messages only contain minimal details that are useful to the intended audience and no one else. The messages need to strike the balance between being too cryptic (which can confuse users) or being too detailed (which may reveal more than intended). The messages should not reveal the methods that were used to determine the error. Attackers can use detailed information to refine or optimize their original attack, thereby increasing their chances of success.
• If errors must be captured in some detail, record them in log messages, but consider what could occur if the log messages can be viewed by attackers. Highly sensitive information such as passwords should never be saved to log files.
• Avoid inconsistent messaging that might accidentally tip off an attacker about internal state, such as whether a user account exists or not.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/215.html
• https://cwe.mitre.org/data/definitions/463.html
• https://cwe.mitre.org/data/definitions/54.html
• https://cwe.mitre.org/data/definitions/7.html

References

• https://github.com/squid-cache/squid/commit/0951a0681011dfca3d78c84fd7f1e19c78a4443f
• https://github.com/squid-cache/squid/security/advisories/GHSA-c8cc-phh7-xmxr
• http://www.openwall.com/lists/oss-security/2025/11/05/6