CVE-2024-42515 is a critical stored Cross-Site Scripting (XSS) vulnerability affecting Glossarizer versions up to 1.5.2. The vulnerability stems from the way Glossarizer attempts to convert text into HTML. While the application itself escapes special characters such as < and > to prevent injection, the underlying library used for rendering converts these escaped characters back into their HTML equivalents. This behavior effectively negates the escaping and allows attackers to inject malicious HTML or JavaScript code. Specifically, attackers can append XSS payloads to words that have corresponding glossary entries, which are then stored and rendered as legitimate HTML content. This stored XSS can lead to arbitrary script execution in the context of the victim's browser, enabling session hijacking, credential theft, or further attacks on users. The vulnerability does not require any authentication or user interaction, making it highly exploitable remotely. The CVSS v3.1 score of 9.9 reflects the vulnerability's critical nature, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and scope change (S:C). The impact on confidentiality is low, but integrity is high, and availability is low, indicating that the primary risk is malicious code execution and data manipulation rather than system downtime. No patches or fixes are currently linked, and no known exploits have been observed in the wild as of the publication date.

The impact of CVE-2024-42515 is significant for organizations using Glossarizer or similar glossary-rendering tools. Successful exploitation allows attackers to execute arbitrary JavaScript in users' browsers, potentially leading to session hijacking, theft of sensitive information, unauthorized actions performed on behalf of users, and distribution of malware. Because the vulnerability is stored XSS, the malicious payload persists on the server and affects all users who view the compromised glossary entries, amplifying the attack's reach. This can lead to reputational damage, regulatory penalties if sensitive data is exposed, and operational disruptions if attackers leverage the vulnerability to escalate attacks. The vulnerability's ease of exploitation without authentication or user interaction increases the risk of widespread automated attacks. Organizations with public-facing web applications integrating Glossarizer are particularly at risk, especially those with high user traffic or handling sensitive user data.

To mitigate CVE-2024-42515, organizations should first check for updates or patches from Glossarizer developers and apply them immediately once available. In the absence of official patches, consider disabling or restricting the use of glossary features that convert text to HTML. Implement additional server-side input validation and sanitization to ensure that glossary entries cannot contain executable scripts or malicious HTML. Employ Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of potential XSS payloads. Regularly audit and sanitize existing glossary entries to remove any injected malicious content. Additionally, monitor web application logs for unusual input patterns or errors related to glossary rendering. Educate developers and administrators about secure coding practices related to HTML encoding and escaping, especially when using third-party libraries that manipulate HTML content. Finally, consider deploying Web Application Firewalls (WAFs) with rules tuned to detect and block XSS payloads targeting glossary features.