CVE-2021-38492

MediumCVSS 6.5/10Last modified Jun 17, 2026

Description

When delegating navigations to the operating system, Firefox would accept the `mk` scheme which might allow attackers to launch pages and execute scripts in Internet Explorer in unprivileged mode. *This bug only affects Firefox for Windows. Other operating systems are unaffected.*. This vulnerability affects Firefox < 92, Thunderbird < 91.1, Thunderbird < 78.14, Firefox ESR < 78.14, and Firefox ESR < 91.1.

Metrics

CVSS 3.1 6.5/10CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

Affected software

No affected versions have been published.

Timeline

Published
Nov 3, 2021
Last modified
Jun 17, 2026
NVD status
Modified

Related CVEs from 2021

CVE-2021-384938.8Mozilla developers reported memory safety bugs present in Firefox 91 and Firefox ESR 78.13. Some of these bugs showed evidence of memory corCVE-2021-384948.8Mozilla developers reported memory safety bugs present in Firefox 91. Some of these bugs showed evidence of memory corruption and we presumeCVE-2021-384958.8Mozilla developers reported memory safety bugs present in Thunderbird 78.13.0. Some of these bugs showed evidence of memory corruption and wCVE-2021-384968.8During operations on MessageTasks, a task may have been removed while it was still scheduled, resulting in memory corruption and a potentialCVE-2021-384976.5Through use of reportValidity() and window.open(), a plain-text validation message could have been overlaid on another origin, leading to poCVE-2021-384987.5During process shutdown, a document could have caused a use-after-free of a languages service object, leading to memory corruption and a potCVE-2021-384998.8Mozilla developers reported memory safety bugs present in Firefox 92. Some of these bugs showed evidence of memory corruption and we presumeCVE-2021-38509.1Authentication Bypass by Primary Weakness in GitHub repository adodb/adodb prior to 5.20.21.CVE-2021-385008.8Mozilla developers reported memory safety bugs present in Firefox 92 and Firefox ESR 91.1. Some of these bugs showed evidence of memory corrCVE-2021-385018.8Mozilla developers reported memory safety bugs present in Firefox 92 and Firefox ESR 91.1. Some of these bugs showed evidence of memory corrCVE-2021-385025.9Thunderbird ignored the configuration to require STARTTLS security for an SMTP connection. A MITM could perform a downgrade attack to intercCVE-2021-3850310.0The iframe sandbox rules were not correctly applied to XSLT stylesheets, allowing an iframe to bypass restrictions such as executing scripts
CVE-2021-38492: Medium severity, CVSS 6.5 | Vulnix