CVE-2025-24598 in WP Mailster Plugin
Summary
by MITRE • 02/04/2025
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in brandtoss WP Mailster allows Reflected XSS. This issue affects WP Mailster: from n/a through 1.8.17.0.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 02/05/2025
The vulnerability CVE-2025-24598 represents a critical cross-site scripting flaw within the brandtoss WP Mailster plugin for WordPress systems. This reflected XSS vulnerability occurs during the web page generation process when the application fails to properly neutralize user input before incorporating it into dynamically generated web content. The flaw specifically impacts versions of WP Mailster ranging from an unspecified starting point through version 1.8.17.0, creating a significant attack surface for malicious actors targeting WordPress installations. The vulnerability stems from inadequate input validation and output encoding mechanisms that allow malicious scripts to be injected into web pages viewed by unsuspecting users.
The technical exploitation of this vulnerability follows the standard reflected XSS attack pattern where an attacker crafts malicious input containing script code and delivers it to a victim through phishing emails, malicious links, or compromised websites. When a victim clicks on the crafted link or visits the malicious page, the script executes in the victim's browser context, potentially stealing session cookies, performing unauthorized actions, or redirecting users to malicious sites. The vulnerability manifests during the web page generation phase when user-supplied parameters are directly incorporated into HTML output without proper sanitization or encoding, creating an environment where attacker-controlled content can execute arbitrary JavaScript code within the victim's browser.
The operational impact of this vulnerability extends beyond simple script execution to encompass potential data breaches, session hijacking, and privilege escalation attacks. Attackers can leverage this vulnerability to gain unauthorized access to user accounts, manipulate email campaigns, or extract sensitive information from the WordPress administration interface. The reflected nature of the vulnerability means that the malicious payload is reflected back to the user through the application's response, making it particularly dangerous as it can be triggered by simply visiting a malicious URL. This vulnerability affects not only individual user sessions but also the overall integrity and security posture of WordPress installations using the affected plugin version.
Security mitigations for CVE-2025-24598 should prioritize immediate patching of the WP Mailster plugin to version 1.8.17.1 or later, which contains the necessary fixes for the XSS vulnerability. Organizations should implement comprehensive input validation and output encoding mechanisms that sanitize all user-supplied data before incorporating it into web page content, following established security practices such as those outlined in the OWASP Top Ten and the CWE-79 category for cross-site scripting. Network administrators should consider implementing web application firewalls and content security policies to provide additional layers of protection against reflected XSS attacks. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and represents a clear violation of the ATT&CK technique T1203 for legitimate access through web application attacks. Regular security audits and vulnerability assessments should be conducted to identify similar input validation weaknesses in other web applications and plugins, ensuring comprehensive protection against similar reflected XSS vulnerabilities that could compromise the entire web infrastructure.