Vulnerability GHSA-465g-fh3v-9jw4

Summary

A query parameter injection vulnerability exists in the AMQP client's connection URI formatting logic. When generating or parsing connection URIs, TLS-related filesystem paths (such as certificates or keys) are appended directly to the URI's query string using string concatenation rather than secure URL encoding via functions like url.QueryEscape.

If an application handles a TLS file path containing special character delimiters (such as & or =), these characters are interpreted as parameter separators by the URI parser. If the resulting URI.String() output is subsequently re-parsed via ParseURI, the injected fields can silently overwrite or hijack critical configuration parameters, forcing the client to use arbitrary connection settings or alternate TLS files.

Attack Vector

An attacker who has partial control over directory naming conventions or environmental variables used to specify local infrastructure paths can execute a parameter injection attack:

1. Path Creation: An attacker sets up a path containing deliberate URL parameter delimiters (e.g., /var/lib/certs/client.crt?cacertfile=/tmp/fake_ca.crt&).
2. String Generation: The application serializes the active connection state or passes the paths down to an unescaped URI builder function.
3. Configuration Hijack: The URI string is generated with the injected parameter embedded into the query structure. When the client attempts to reuse or re-parse this connection string during a connection retry or worker spin-up, it parses the injected cacertfile parameter, loading a different, unverified Certificate Authority string.