CVE-2021-43332 in Mailman
Summary
by MITRE • 11/13/2021
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.
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Analysis
by VulDB Data Team • 11/16/2021
The vulnerability identified as CVE-2021-43332 represents a critical security flaw in GNU Mailman versions prior to 2.1.36 that directly impacts the integrity of administrative access controls. This issue stems from the improper implementation of Cross-Site Request Forgery protection mechanisms within the web-based administrative interface, specifically affecting the Cgi/admindb.py page that handles database administration tasks. The flaw demonstrates a fundamental weakness in how the system generates and manages security tokens for administrative operations, creating a pathway for unauthorized access that could compromise entire mailing list systems.
The technical implementation of this vulnerability involves the inclusion of an encrypted representation of the list administrator password within the CSRF token itself. This design decision fundamentally violates security best practices by embedding sensitive authentication information within what should be a simple anti-CSRF protection mechanism. The encrypted password component within the token creates a potential attack vector where a malicious actor with access to the administrative interface could potentially perform offline brute-force attacks against the token to recover the original password. This approach directly contravenes the principle of keeping authentication credentials separate from anti-CSRF tokens, which is a core tenet of secure web application design.
From an operational perspective, this vulnerability creates significant risk for organizations relying on GNU Mailman for email list management, particularly those with sensitive or high-traffic mailing lists. The potential for offline brute-force attacks means that even if a moderator's session is not actively compromised, the embedded password information within the CSRF token provides an attack surface that could be exploited at a later time. The impact extends beyond simple unauthorized access to include potential data breaches, spam distribution, and the ability to modify or delete mailing list configurations. Organizations using affected versions face the risk of complete administrative compromise, which could lead to widespread disruption of email communications and potential security breaches within their network infrastructure.
The vulnerability aligns with CWE-352, which specifically addresses Cross-Site Request Forgery, and demonstrates poor implementation of secure token generation practices. From an ATT&CK framework perspective, this represents a technique that could be leveraged under the T1110 credential access category, potentially enabling adversaries to escalate privileges through the compromise of administrative credentials. The flaw also intersects with T1566 initial access techniques, as the vulnerability could be exploited through web-based attack vectors targeting the administrative interface. Organizations should consider this vulnerability as part of a broader attack surface that includes web application security, session management, and authentication system integrity. The recommended mitigation involves immediate upgrade to GNU Mailman version 2.1.36 or later, which implements proper CSRF token generation without embedding sensitive credential information, along with regular security auditing of web applications to ensure compliance with secure coding practices and proper separation of authentication and authorization mechanisms.