CVE-2016-20082 in Abtest
Summary
by MITRE • 06/15/2026
WordPress Plugin Abtest contains a local file inclusion vulnerability that allows unauthenticated attackers to include arbitrary files by manipulating the action parameter. Attackers can send GET requests to abtest_admin.php with malicious action values to include files from the admin directory and execute arbitrary code.
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Analysis
by VulDB Data Team • 06/15/2026
The WordPress plugin abtest presents a critical local file inclusion vulnerability that fundamentally undermines the security posture of affected systems. This vulnerability resides in the plugin's handling of the action parameter within the abtest_admin.php file, creating an attack vector that requires no authentication credentials for exploitation. The flaw enables attackers to manipulate the action parameter through GET requests, effectively bypassing normal access controls and gaining unauthorized access to the system's administrative functions. Such vulnerabilities fall under the CWE-22 category of Improper Limitation of a Pathname to a Restricted Directory, commonly known as Path Traversal, which represents one of the most prevalent and dangerous classes of web application vulnerabilities according to the CWE database.
The technical implementation of this vulnerability allows attackers to construct malicious URLs that target the abtest_admin.php endpoint with crafted action parameters. When processed by the vulnerable plugin, these parameters trigger the inclusion of arbitrary files from the server's filesystem, specifically targeting directories within the admin structure. The exploitation process typically involves crafting a request that includes a path traversal sequence or direct file reference, enabling the attacker to include and subsequently execute malicious code within the context of the web application. This vulnerability directly maps to the ATT&CK technique T1059.007 for Command and Scripting Interpreter: PowerShell, as attackers can leverage the included files to execute arbitrary commands on the compromised system. The lack of proper input validation and sanitization creates an environment where attacker-controlled data can be interpreted as legitimate file paths, leading to unauthorized code execution and potential system compromise.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a foothold for further reconnaissance and lateral movement within the compromised environment. Once an attacker successfully exploits this vulnerability, they can access administrative functions, modify plugin configurations, and potentially escalate privileges to gain full control over the WordPress installation. The vulnerability's unauthenticated nature makes it particularly dangerous as it requires no prior access credentials, allowing attackers to immediately begin exploitation upon discovering a vulnerable system. This type of vulnerability can result in complete system compromise, data exfiltration, and the installation of backdoors or additional malware. The attack surface is further expanded as WordPress installations often contain sensitive data, user credentials, and business-critical information that becomes accessible through such exploitation paths.
Effective mitigation strategies for this vulnerability must address both immediate remediation and long-term security hardening measures. The primary recommendation involves updating the affected plugin to the latest version where the vulnerability has been patched, as this directly resolves the flawed parameter handling logic. Additionally, implementing proper input validation and sanitization measures can prevent malicious path traversal attempts from being processed. Web application firewalls should be configured to detect and block suspicious patterns in URL parameters, particularly those containing directory traversal sequences such as ../ or ..\.. This approach aligns with the ATT&CK technique T1566.002 for Initial Access: Phishing via Spearphishing Attachment, where security controls can prevent the exploitation of such vulnerabilities. Organizations should also consider implementing principle of least privilege access controls, restricting file inclusion paths, and conducting regular security audits of WordPress plugins to identify and remediate similar vulnerabilities. The vulnerability highlights the importance of proper secure coding practices, including input validation, output encoding, and secure file handling, as outlined in the OWASP Top Ten and other industry security frameworks.