Impact
PDF.js versions 4.1.392 and earlier are susceptible to a vulnerability that allows for arbitrary JavaScript execution [S2]. This issue, identified as CVE-2024-4367, carries a high severity rating with a CVSS score of 8.8 [S1]. An attacker can exploit this by tricking a user into opening a specially crafted PDF file, which then executes malicious code within the context of the user's browser session [S2]. This can lead to cross-site scripting (XSS), session hijacking, and the theft of sensitive information [S2].
Root Cause
The vulnerability stems from improper handling of specific PDF features, where the library fails to adequately sanitize or check for unusual conditions before rendering [S1]. This lack of validation allows malicious scripts embedded in a PDF to be executed during the processing phase [S2].
Remediation
The primary fix for this vulnerability is to update the pdfjs-dist library to version 4.2.67 or later [S2]. Additionally, implementing a strict Content Security Policy (CSP) can provide a layer of defense-in-depth against the execution of unauthorized scripts [S2].
Detection Strategy
Detection of this vulnerability focuses on identifying the presence of affected library versions within an application's environment [S2].
- Dependency Analysis: Scanning project manifests and lockfiles (such as
package.jsonorpackage-lock.json) forpdfjs-distversions at or below 4.1.392 [S2]. - Version Fingerprinting: Inspecting the version strings of loaded JavaScript assets in a web environment to identify vulnerable instances of the PDF.js library [S2].