CVE-2018-10081 in CMS Made Simple
Summary
by MITRE
CMS Made Simple (CMSMS) through 2.2.6 contains an admin password reset vulnerability because data values are improperly compared, as demonstrated by a hash beginning with the "0e" substring.
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Analysis
by VulDB Data Team • 01/24/2020
The vulnerability identified as CVE-2018-10081 affects CMS Made Simple versions up to 2.2.6 and represents a critical authentication bypass flaw that exploits improper data comparison mechanisms. This vulnerability specifically targets the administrative password reset functionality within the content management system, creating a pathway for unauthorized access to administrative accounts. The flaw stems from how the system handles hash comparisons during the password reset process, particularly when dealing with hashes that begin with the "0e" substring. This particular hash format triggers a mathematical interpretation issue in the comparison logic that allows attackers to bypass authentication requirements through crafted hash values.
The technical implementation of this vulnerability resides in the core authentication module where password reset tokens are validated against stored hash values. When an attacker submits a password reset request with a specially crafted hash beginning with "0e", the comparison function fails to properly validate the input due to PHP's loose comparison behavior. This occurs because PHP's type juggling interprets the "0e" prefixed hash as a scientific notation number, effectively converting it to zero, which then matches the expected hash value in certain comparison contexts. This behavior aligns with CWE-697, which addresses improper comparison issues that can lead to authentication bypasses and similar security flaws. The vulnerability demonstrates a classic example of how insecure comparison logic can be exploited to undermine authentication mechanisms, particularly in web applications that rely on cryptographic hashes for security validation.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with full administrative control over affected CMSMS installations. Once an attacker successfully exploits this vulnerability, they gain complete access to the content management system, allowing them to modify website content, add malicious code, steal sensitive data, and potentially use the compromised system as a launch point for further attacks within the network. The vulnerability's exploitation does not require prior authentication, making it particularly dangerous as attackers can target any administrative account without needing to know existing credentials. This flaw significantly increases the attack surface for organizations using CMSMS, as it allows for automated exploitation and can be leveraged in large-scale attacks against multiple systems. The vulnerability also demonstrates the importance of proper input validation and secure coding practices, as the issue could have been prevented through more robust hash comparison mechanisms that avoid the use of loose comparisons in security-critical contexts.
Organizations affected by this vulnerability should immediately implement mitigations including upgrading to CMSMS version 2.2.7 or later, which contains the necessary patches to address the hash comparison issue. The fix typically involves implementing strict type comparisons rather than loose comparisons, ensuring that hash values are validated using secure cryptographic functions that prevent the mathematical interpretation issues. Security teams should also conduct thorough audits of their CMSMS installations to identify any potential exploitation attempts and monitor for unusual administrative activities. Additional mitigations include implementing rate limiting on password reset requests, enhancing monitoring of authentication-related events, and ensuring that all administrative accounts have strong, unique passwords. This vulnerability highlights the necessity of following secure coding practices as outlined in the OWASP Top Ten and aligns with ATT&CK techniques related to credential access and privilege escalation, specifically covering methods for bypassing authentication mechanisms and gaining administrative access through software flaws.