CVE-2015-8626 in MediaWiki
Summary
by MITRE
The User::randomPassword function in MediaWiki before 1.23.12, 1.24.x before 1.24.5, 1.25.x before 1.25.4, and 1.26.x before 1.26.1 generates passwords smaller than $wgMinimalPasswordLength, which makes it easier for remote attackers to obtain access via a brute-force attack.
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2015-8626 represents a critical weakness in MediaWiki's password generation mechanism that directly impacts user account security across multiple versions of the popular wiki platform. This issue affects MediaWiki installations running versions prior to 1.23.12, 1.24.x prior to 1.24.5, 1.25.x prior to 1.25.4, and 1.26.x prior to 1.26.1, creating a significant attack surface for malicious actors seeking unauthorized access to user accounts. The flaw specifically resides within the User::randomPassword function which is responsible for generating secure passwords for new user accounts or password resets.
The technical implementation of this vulnerability stems from a failure in the password generation algorithm where the randomPassword function does not properly enforce the minimum password length requirements defined by the $wgMinimalPasswordLength configuration variable. This configuration parameter is designed to ensure that all generated passwords meet a minimum complexity threshold that provides adequate security against various attack vectors including brute-force attempts. When the function fails to respect this minimum length requirement, it creates passwords that are significantly shorter than the configured security baseline, thereby reducing the entropy and making these passwords more susceptible to successful brute-force attacks.
The operational impact of this vulnerability is substantial as it directly enables remote attackers to conduct more effective brute-force attacks against user accounts. Attackers can exploit the weakened password generation to systematically guess or crack user passwords with reduced computational effort compared to attacking properly generated passwords of sufficient length. This vulnerability particularly affects systems where MediaWiki is used for user authentication and account management, potentially leading to unauthorized access to sensitive information, account takeovers, and compromise of the entire wiki platform. The reduced password complexity creates a cascading security risk that extends beyond individual accounts to potentially affect the broader system integrity and user trust in the platform's security mechanisms.
From a cybersecurity framework perspective, this vulnerability maps to CWE-326: Inadequate Encryption Strength and CWE-327: Use of a Broken or Risky Cryptographic Algorithm, as it involves improper implementation of cryptographic functions that should ensure adequate password entropy. The attack surface aligns with ATT&CK technique T1110.003: Brute Force: Password Guessing, where adversaries leverage weak password generation to facilitate successful credential compromise. Organizations should immediately implement mitigations including upgrading to patched versions of MediaWiki, enforcing stricter password policies, and monitoring for unauthorized access attempts. Additionally, system administrators should conduct comprehensive security audits to identify any compromised accounts and consider implementing multi-factor authentication as an additional security layer to protect against this specific vulnerability's exploitation.