An issue was discovered in Mailman Core before 3.3.5. An attacker with access to the REST API could use timing attacks to determine the value of the configured REST API password and then make arbitrary REST API calls. The REST API is bound to localhost by default, limiting the ability for attackers to exploit this, but can optionally be made to listen on other interfaces.

In GNU Mailman before 2.1.38, a list member or moderator can get a CSRF token and craft an admin request (using that token) to set a new admin password or make other changes.

In GNU Mailman before 2.1.36, a crafted URL to the Cgi/options.py user options page can execute arbitrary JavaScript for XSS.

In GNU Mailman before 2.1.36, the CSRF token for the Cgi/admindb.py admindb page contains an encrypted version of the list admin password. This could potentially be cracked by a moderator via an offline brute-force attack.

GNU Mailman before 2.1.35 may allow remote Privilege Escalation. A certain csrf_token value is derived from the admin password, and may be useful in conducting a brute-force attack against that password.

GNU Mailman before 2.1.35 may allow remote Privilege Escalation. A csrf_token value is not specific to a single user account. An attacker can obtain a value within the context of an unprivileged user account, and then use that value in a CSRF attack against an admin (e.g., for account takeover).

The GNU-Mailman Integration WordPress plugin is vulnerable to Reflected Cross-Site Scripting via the gm_error parameter found in the ~/includes/admin/mailing-lists-page.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 1.0.6.

GNU Mailman before 2.1.33 allows arbitrary content injection via the Cgi/private.py private archive login page.

/options/mailman in GNU Mailman before 2.1.31 allows Arbitrary Content Injection.

GNU Mailman 2.x before 2.1.30 uses the .obj extension for scrubbed application/octet-stream MIME parts. This behavior may contribute to XSS attacks against list-archive visitors, because an HTTP reply from an archive web server may lack a MIME type, and a web browser may perform MIME sniffing, conclude that the MIME type should have been text/html, and execute JavaScript code.