CVE-2022-4829 in Show-Hide Collapse-Expand Plugin
Summary
by MITRE • 02/27/2023
The Show-Hide / Collapse-Expand WordPress plugin through 1.2.5 does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admins.
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Analysis
by VulDB Data Team • 03/25/2023
The vulnerability identified as CVE-2022-4829 affects the Show-Hide / Collapse-Expand WordPress plugin version 1.2.5 and earlier, representing a critical security flaw that undermines the integrity of WordPress sites relying on this plugin. This issue stems from insufficient input validation and output escaping mechanisms within the plugin's shortcode implementation, creating an avenue for malicious actors to inject persistent malicious scripts into web pages. The vulnerability is particularly concerning because it can be exploited by users with relatively low privileges, specifically contributors who typically have limited capabilities within WordPress environments. This privilege escalation potential makes the vulnerability especially dangerous as it allows attackers to compromise high-privilege accounts such as administrators through carefully crafted malicious payloads.
The technical flaw manifests in the plugin's failure to properly sanitize shortcode attributes before rendering them in web pages. When users with contributor roles create or modify content using the plugin's shortcodes, the system does not adequately validate or escape user-supplied parameters before incorporating them into the HTML output. This oversight creates a stored cross-site scripting vulnerability where malicious scripts can be permanently embedded within the website's content and executed whenever legitimate users access pages containing the compromised shortcodes. The vulnerability operates through the standard WordPress shortcode processing mechanism, where user input is parsed and rendered without sufficient security measures to prevent malicious code injection.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers to perform sophisticated attacks against high-privilege users. When administrators or other elevated users view pages containing the malicious shortcodes, their browsers execute the embedded scripts, potentially allowing attackers to steal session cookies, perform unauthorized administrative actions, or redirect users to malicious sites. The stored nature of this vulnerability means that once a malicious shortcode is injected, it persists on the website until manually removed, creating a long-term threat vector that can affect multiple users over extended periods. This persistent threat is particularly dangerous in multi-user environments where administrators regularly access content created by contributors.
From a cybersecurity perspective, this vulnerability aligns with CWE-79 (Cross-Site Scripting) and represents a prime example of how insufficient input validation can create severe security implications. The ATT&CK framework categorizes this vulnerability under TA0001 (Initial Access) and TA0002 (Execution) techniques, as attackers can leverage it to gain initial access through malicious content and then execute arbitrary code against target systems. The vulnerability also demonstrates characteristics of privilege escalation through web application flaws, where low-privilege users can manipulate application behavior to affect higher-privilege accounts. Organizations should immediately implement mitigation strategies including plugin updates, input validation enforcement, and user role restrictions to prevent exploitation of this vulnerability. The recommended approach involves patching to the latest plugin version, implementing proper content filtering, and conducting regular security audits to identify similar vulnerabilities in other third-party components.