CVE-2024-32489 is a vulnerability identified in TCPDF, an open-source PHP library widely used for generating PDF documents from HTML content. Versions prior to 6.7.4 mishandle calls that include HTML syntax, specifically failing to properly sanitize or encode HTML input. This flaw corresponds to CWE-80 (Improper Neutralization of Script-Related HTML Tags in a Web Page), which typically leads to cross-site scripting (XSS) vulnerabilities. An attacker can craft malicious HTML or JavaScript code that, when processed by the vulnerable TCPDF library, may be embedded into generated PDF documents or web pages, potentially executing in the context of the victim’s browser. The CVSS 3.1 base score of 6.1 indicates a medium severity, with an attack vector of network (remote exploitation), low attack complexity, no privileges required, but user interaction is necessary (e.g., a user must open or view the crafted PDF or web content). The scope is changed, meaning the vulnerability can affect components beyond the vulnerable library itself. Confidentiality and integrity impacts are limited but present, while availability is unaffected. No known exploits have been reported in the wild as of the publication date, but the vulnerability poses a risk to any web application or service that uses TCPDF to process untrusted HTML input. Since TCPDF is commonly integrated into content management systems, customer portals, and document generation workflows, the vulnerability could be leveraged to perform phishing, session hijacking, or other client-side attacks if exploited.

For European organizations, this vulnerability could lead to client-side attacks such as XSS, enabling attackers to steal session tokens, manipulate displayed content, or perform actions on behalf of users. This is particularly critical for sectors relying heavily on web applications that generate dynamic PDFs or display user-generated HTML content, such as finance, healthcare, government, and e-commerce. The confidentiality of sensitive user data could be compromised, and the integrity of documents or displayed information could be undermined, potentially damaging trust and compliance with regulations like GDPR. Although availability is not impacted, the reputational damage and potential regulatory penalties from data breaches could be significant. Organizations that do not promptly patch or mitigate this vulnerability risk exploitation through phishing campaigns or targeted attacks leveraging crafted PDF documents or web pages.

1. Upgrade TCPDF to version 6.7.4 or later, where the vulnerability has been addressed. 2. Implement strict input validation and sanitization on all HTML content before it is processed by TCPDF, ensuring that potentially malicious scripts or tags are removed or neutralized. 3. Employ output encoding techniques when rendering HTML content to prevent script execution in client browsers. 4. Use Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of potential XSS attacks. 5. Conduct regular security audits and code reviews of applications integrating TCPDF to identify and remediate unsafe HTML handling. 6. Educate users to be cautious when opening PDF documents from untrusted sources to reduce the risk of social engineering exploitation. 7. Monitor web application logs and network traffic for unusual activity that could indicate exploitation attempts.