CVE-2022-2891 in WP 2FA Plugin
Summary
by MITRE • 10/11/2022
The WP 2FA WordPress plugin before 2.3.0 uses comparison operators that don't mitigate time-based attacks, which could be abused to leak information about the authentication codes being compared.
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Analysis
by VulDB Data Team • 05/28/2026
The WP 2FA WordPress plugin vulnerability represents a critical timing side-channel attack surface that emerged from improper implementation of cryptographic comparison operations. This flaw exists in versions prior to 2.3.0 and specifically affects the plugin's handling of two-factor authentication codes during the verification process. The vulnerability stems from the use of non-constant time comparison operators that reveal timing information about the authentication codes being validated, creating opportunities for attackers to exploit temporal patterns in code execution.
The technical implementation flaw manifests through the use of standard equality comparison operators instead of constant-time comparison functions when validating one-time passwords or authentication tokens. This pattern directly violates established security practices outlined in the CWE-209 weakness category, which addresses timing attacks and information leakage through side channels. When an attacker submits multiple authentication attempts, the system's response time varies based on how many characters match between the submitted code and the expected value, creating a measurable timing differential that can be exploited through statistical analysis.
This vulnerability enables attackers to perform brute force attacks with significantly reduced computational overhead compared to traditional methods. The timing variations allow for the gradual revelation of authentication code components, effectively reducing the entropy of the security mechanism. Attackers can systematically test code segments and measure response times to determine correct character positions, making the two-factor authentication system vulnerable to automated exploitation. The impact extends beyond simple credential theft, as successful exploitation can lead to full administrative access to WordPress installations, particularly when combined with other attack vectors.
The operational impact of this vulnerability is substantial for WordPress administrators who rely on the WP 2FA plugin for security. Organizations using vulnerable versions face increased risk of unauthorized access to their web applications, potentially leading to data breaches, defacement, or further exploitation of compromised systems. The vulnerability aligns with ATT&CK technique T1110.003, which covers credential stuffing and brute force attacks, while also mapping to T1212, which addresses exploitation of information disclosure vulnerabilities. The timing-based attack vector makes this particularly dangerous as it can be executed remotely without requiring physical access or complex infrastructure.
Mitigation strategies should prioritize immediate patching of the WP 2FA plugin to version 2.3.0 or later, which implements proper constant-time comparison algorithms. Administrators should also consider implementing additional security measures such as rate limiting, IP address restrictions, and monitoring for unusual authentication patterns. The vulnerability demonstrates the critical importance of adhering to cryptographic best practices, particularly the requirement for constant-time operations in security-sensitive contexts. Organizations should conduct comprehensive security assessments of their WordPress installations to identify similar vulnerabilities in other plugins or custom code implementations that may be susceptible to timing-based attacks.