CVE-2008-1930 in WordPress
Summary
by MITRE
The cookie authentication method in WordPress 2.5 relies on a hash of a concatenated string containing USERNAME and EXPIRY_TIME, which allows remote attackers to forge cookies by registering a username that results in the same concatenated string, as demonstrated by registering usernames beginning with "admin" to obtain administrator privileges, aka a "cryptographic splicing" issue. NOTE: this vulnerability exists because of an incomplete fix for CVE-2007-6013.
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Analysis
by VulDB Data Team • 08/09/2019
The vulnerability described in CVE-2008-1930 represents a critical cryptographic weakness in WordPress 2.5's authentication system that stems from improper hash generation and validation mechanisms. This issue specifically affects the cookie-based authentication method that WordPress employs to maintain user sessions and privileges. The flaw arises from the implementation of a cryptographic splicing attack vector where attackers can exploit the predictable nature of hash computations to forge valid authentication cookies without possessing legitimate credentials. The vulnerability is particularly concerning because it directly undermines the core security model of web applications by allowing unauthorized privilege escalation through carefully crafted username registration.
The technical implementation of this vulnerability exploits a fundamental flaw in how WordPress 2.5 handles authentication tokens. The system generates authentication cookies by creating a hash of a concatenated string that includes both the username and expiry time, which should provide sufficient entropy for security. However, the implementation suffers from inadequate cryptographic practices that make it susceptible to collision attacks. Attackers can register usernames that, when processed through the same hash algorithm, produce identical or predictable hash values that match valid administrator cookies. This vulnerability specifically demonstrates the weakness in the hash function's resistance to preimage attacks, where an attacker can determine the input values that produce a specific hash output. The issue is categorized under CWE-327, which deals with the use of a broken or weak cryptographic algorithm, and more specifically relates to CWE-328, which addresses the use of weak hash functions.
The operational impact of this vulnerability extends beyond simple privilege escalation to represent a complete breakdown in the application's access control mechanisms. An attacker who successfully exploits this vulnerability can gain administrative privileges without knowledge of valid passwords or other authentication credentials, effectively compromising the entire WordPress installation. This allows for complete control over the website including content manipulation, user management, plugin installation, and potentially the ability to use the compromised system as a platform for further attacks against other systems. The attack vector is particularly insidious because it requires minimal technical expertise and can be executed through simple username registration processes, making it accessible to attackers with basic web application knowledge. The vulnerability also demonstrates the importance of proper cryptographic implementation practices and the dangers of reusing or modifying existing hash functions without proper security analysis.
The root cause of this vulnerability lies in the incomplete fix for CVE-2007-6013, which indicates a pattern of security regressions that occur when security patches are implemented without thorough analysis of the underlying cryptographic principles. This demonstrates the critical importance of maintaining proper security practices throughout the software development lifecycle, including comprehensive testing of cryptographic implementations and adherence to established security standards. The vulnerability serves as a prime example of how seemingly minor implementation details in cryptographic systems can have catastrophic security implications. Organizations should implement multiple layers of security controls including regular security audits, proper input validation, and robust authentication mechanisms to prevent such vulnerabilities from being exploited. The remediation process requires immediate patching of the affected WordPress version, implementation of stronger cryptographic algorithms, and potentially the complete redesign of the authentication cookie generation process to ensure proper entropy and resistance to collision attacks. This vulnerability also underscores the necessity of following established security frameworks such as the NIST guidelines for cryptographic key management and the OWASP Top Ten security principles to prevent similar issues in future implementations.