CVE-2020-36729 in 2J-SlideShow Plugin
Summary
by MITRE • 06/07/2023
The 2J-SlideShow Plugin for WordPress is vulnerable to authorization bypass due to a missing capability check on the 'twoj_slideshow_setup' function called via the wp_ajax_twoj_slideshow_setup AJAX action in versions up to, and including, 1.3.31. This makes it possible for authenticated attackers (Subscriber, or above level access) to allow attackers to perform otherwise restricted actions and subsequently deactivate any plugins on the blog.
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Analysis
by VulDB Data Team • 07/05/2023
The CVE-2020-36729 vulnerability represents a critical authorization bypass flaw within the 2J-SlideShow WordPress plugin, affecting versions through 1.3.31. This vulnerability stems from a fundamental security oversight in the plugin's AJAX handling mechanism where the 'twoj_slideshow_setup' function lacks proper capability verification. The issue manifests through the wp_ajax_twoj_slideshow_setup AJAX action which serves as an entry point for malicious exploitation, allowing attackers to bypass the intended access controls that should restrict plugin management functions to administrators only.
The technical implementation of this vulnerability exposes a clear gap in the plugin's permission model where the AJAX handler does not validate user capabilities before executing sensitive operations. This missing capability check creates a pathway for authenticated users with Subscriber level privileges or higher to escalate their privileges and execute restricted administrative functions. The vulnerability specifically targets the plugin's setup functionality which, when improperly accessed, enables attackers to manipulate plugin states and potentially deactivate critical security plugins, thereby undermining the overall security posture of the WordPress installation.
From an operational perspective, this vulnerability significantly impacts the security landscape of affected WordPress sites by allowing low-privilege attackers to gain unauthorized access to plugin management capabilities. The ability to deactivate plugins provides attackers with a powerful weapon for disrupting site operations or removing security measures that might be protecting against other attacks. This authorization bypass creates a persistent threat vector that can be exploited repeatedly, as long as the attacker maintains access to an account with Subscriber level privileges or higher, potentially leading to complete site compromise or service disruption.
The vulnerability aligns with CWE-863, which addresses "Incorrect Authorization" issues in software systems where access control mechanisms fail to properly validate user permissions. This misconfiguration creates an attack surface that can be leveraged through the ATT&CK framework's privilege escalation techniques, specifically targeting the 'Abuse Elevation of Privilege' tactic. The exploitation pathway demonstrates how seemingly minor security gaps in plugin development can create substantial risks for WordPress installations, particularly when plugins fail to implement proper input validation and capability checks for AJAX endpoints that handle administrative functions.
Mitigation strategies should prioritize immediate plugin updates to versions that address the capability check deficiency, as well as implementing additional security measures such as role-based access restrictions and monitoring for unusual plugin activity. Site administrators should also consider implementing web application firewalls to detect and block suspicious AJAX requests, while conducting thorough security audits of all installed plugins to identify similar authorization bypass vulnerabilities. The remediation process must include verification that the updated plugin properly implements capability checks and that no other AJAX endpoints within the same plugin or related components suffer from similar authorization flaws.