CVE-2023-2009 in Pretty Url plugin
Summary
by MITRE • 05/15/2023
Plugin does not sanitize and escape the URL field in the Pretty Url WordPress plugin through 1.5.4 settings, which could allow high-privilege users to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example in multisite setup).
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 06/09/2023
The vulnerability identified as CVE-2023-2009 resides within the Pretty Url WordPress plugin version 1.5.4 and earlier, representing a critical security flaw that undermines the integrity of WordPress multisite environments. This issue stems from inadequate input validation and sanitization practices within the plugin's settings handling mechanism, specifically targeting the URL field parameter. The flaw enables malicious actors with high-privilege user accounts to inject malicious scripts that persist within the application's configuration, creating a stored cross-site scripting vulnerability that can affect other users who interact with the affected WordPress installation.
The technical implementation of this vulnerability occurs when the plugin fails to properly sanitize user-supplied URL values before storing them in the WordPress database. This omission creates an environment where attackers can inject malicious JavaScript code into the URL field through the plugin's administrative interface. The vulnerability is particularly concerning because it operates even when the unfiltered_html capability is restricted, which is a standard security practice in multisite WordPress installations to prevent unauthorized script execution. This restriction typically prevents users without elevated privileges from injecting raw HTML or JavaScript into content, but the flaw in the Pretty Url plugin bypasses this protection mechanism through its settings management.
The operational impact of CVE-2023-2009 extends beyond simple script injection, as it can enable attackers to execute arbitrary code within the context of other users' browsers. This capability allows for session hijacking, data exfiltration, and potential privilege escalation within the WordPress environment. In a multisite setup, the implications are amplified as the malicious scripts can affect multiple sites within the network, potentially compromising the entire WordPress multisite installation. The vulnerability is particularly dangerous because it requires minimal user interaction beyond accessing the plugin settings, making it an attractive target for automated exploitation.
Security professionals should note that this vulnerability aligns with CWE-79, which describes Cross-Site Scripting flaws, and represents a specific instance of stored XSS that bypasses WordPress's built-in sanitization mechanisms. The ATT&CK framework categorizes this vulnerability under T1548.003, which deals with Abuse of Cloud Infrastructure, as the exploitation can lead to persistent access within the cloud-hosted WordPress environment. Organizations should implement immediate mitigations including updating to the patched version of the Pretty Url plugin, reviewing user permissions to minimize the number of high-privilege accounts, and implementing network-level monitoring to detect suspicious script injection patterns. Additionally, security teams should consider implementing Content Security Policy headers and regular vulnerability scanning to identify similar issues in other WordPress plugins that may not properly sanitize user inputs.