CVE-2024-4367

A type check was missing when handling fonts in PDF.js, which would allow arbitrary JavaScript execution in the PDF.js context. This vulnerability affects Firefox < 126, Firefox ESR < 115.11, and Thunderbird < 115.11.

A type check was missing when handling fonts in PDF.js, which would allow arbitrary JavaScript execution in the PDF.js context. This vulnerability affects Firefox < 126, Firefox ESR < 115.11, and Thunderbird < 115.11.

### Impact If 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 will be executed in the context of the hosting domain. ### Patches The patch removes the use of `eval`: https://github.com/mozilla/pdf.js/pull/18015 ### Workarounds Set the option `isEvalSupported` to `false`. ### References https://bugzilla.mozilla.org/show_bug.cgi?id=1893645

### Impact If 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 will be executed in the context of the hosting domain. ### Patches The patch removes the use of `eval`: https://github.com/mozilla/pdf.js/pull/18015 ### Workarounds Set the option `isEvalSupported` to `false`. ### References https://bugzilla.mozilla.org/show_bug.cgi?id=1893645

Faltaba una verificación de tipo al manejar fuentes en PDF.js, lo que permitiría la ejecución arbitraria de JavaScript en el contexto de PDF.js. Esta vulnerabilidad afecta a Firefox &lt; 126, Firefox ESR &lt; 115.11 y Thunderbird &lt; 115.11.