CVE-2016-2041 in phpMyAdmin
Summary
by MITRE
libraries/common.inc.php in phpMyAdmin 4.0.x before 4.0.10.13, 4.4.x before 4.4.15.3, and 4.5.x before 4.5.4 does not use a constant-time algorithm for comparing CSRF tokens, which makes it easier for remote attackers to bypass intended access restrictions by measuring time differences.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 07/08/2022
The vulnerability identified as CVE-2016-2041 affects phpMyAdmin versions prior to specific patched releases, creating a timing side-channel attack vector that undermines the security of cross-site request forgery protection mechanisms. This flaw exists within the libraries/common.inc.php file where the application fails to implement a constant-time algorithm for comparing CSRF tokens, a critical security measure designed to prevent unauthorized actions. The vulnerability allows remote attackers to exploit timing differences in token comparison operations to bypass intended access restrictions, effectively weakening the application's authentication and authorization controls.
The technical implementation flaw stems from the application's use of variable-time string comparison functions that execute different numbers of operations depending on the position of mismatched characters. When comparing CSRF tokens, attackers can measure the time differences between successful and failed comparisons to determine the correct token values through statistical analysis and repeated attempts. This timing-based approach aligns with the common patterns described in CWE-203, which addresses "Information Exposure Through Timing Discrepancies" and represents a well-documented class of vulnerabilities in cryptographic implementations. The vulnerability specifically impacts the cryptographic operations within the application's security framework, making it susceptible to timing attacks that can be executed remotely without requiring authentication or special privileges.
The operational impact of this vulnerability extends beyond simple access bypass to potentially enable more serious security compromises within the phpMyAdmin environment. Attackers who successfully exploit this timing weakness can gain unauthorized access to database management interfaces, potentially leading to data theft, modification of database contents, or privilege escalation within the database system. The vulnerability affects multiple version streams of phpMyAdmin, indicating a widespread issue that would impact numerous installations across different organizational environments. This makes it particularly dangerous as administrators may be unaware of the vulnerability in their specific version, creating a window of opportunity for exploitation that could remain undetected for extended periods.
Organizations affected by this vulnerability should immediately implement the available patches for phpMyAdmin versions 4.0.10.13, 4.4.15.3, and 4.5.4, which address the timing side-channel issue by implementing constant-time token comparison algorithms. The mitigation strategy should include comprehensive testing of patched installations to ensure that the timing discrepancy has been eliminated and that normal application functionality remains intact. Additionally, organizations should consider implementing network-level monitoring to detect potential timing-based attacks and establish regular vulnerability assessment procedures to identify similar issues in other applications. The vulnerability demonstrates the importance of proper cryptographic implementation practices and aligns with ATT&CK technique T1212, which covers "Exploitation for Credential Access" through timing attacks, emphasizing that even seemingly minor implementation flaws can create significant security risks in web applications.