CVE-2024-34342: 
JavaScript vulnerability analysis and mitigation

CVE-2024-34342 affects react-pdf, a popular npm package for displaying PDFs within React applications. The vulnerability was discovered by security researcher Thomas Rinsma and disclosed on May 7, 2024. When PDF.js is used to load a malicious PDF, and PDF.js is configured with isEvalSupported set to true (which is the default value), unrestricted attacker-controlled JavaScript can be executed in the context of the hosting domain. The vulnerability affects react-pdf versions up to 7.7.2 and from 8.0.0 to 8.0.1 (React PDF Advisory).

The vulnerability has been assigned a CVSS v3.1 base score of 7.1 (High) with the vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L. The issue stems from the default configuration of isEvalSupported being set to true, which allows for the execution of arbitrary JavaScript code when processing malicious PDF files. The vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation) (NVD).

The vulnerability has a significant impact due to react-pdf's widespread usage, with over 600,000 downloads per week from npm. When exploited, attackers can execute unrestricted JavaScript code in the context of the hosting domain, potentially leading to data theft, cookie stealing, session token compromise, and unauthorized actions on behalf of users (Security Online).

The vulnerability has been patched in react-pdf versions 7.7.3 and 8.0.2 by forcing isEvalSupported to false. For users unable to upgrade immediately, a workaround is available by explicitly setting the isEvalSupported option to false within the Document component's options prop (React PDF Commit).