Mozilla Foundation Security Advisory 2021-38
Security Vulnerabilities fixed in Firefox 92
- Announced
- September 7, 2021
- Impact
- high
- Products
- Firefox
- Fixed in
-
- Firefox 92
#CVE-2021-29993: Handling custom intents could lead to crashes and UI spoofs
- Reporter
- Amy Burnett working with Include Security
- Impact
- high
Description
Firefox for Android allowed navigations through the intent:// protocol, which could be used to cause crashes and UI spoofs.
This bug only affects Firefox for Android. Other operating systems are unaffected.
References
#CVE-2021-38491: Mixed-Content-Blocking was unable to check opaque origins
- Reporter
- Jonathan Kingston
- Impact
- moderate
Description
Mixed-content checks were unable to analyze opaque origins which led to some mixed content being loaded.
References
#CVE-2021-38492: Navigating to "mk:" URL scheme could load Internet Explorer
- Reporter
- James Lee
- Impact
- moderate
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.
References
#CVE-2021-4221: Address bar spoofing on Firefox for Android due to RTL characters
- Reporter
- Rohan Sharma
- Impact
- moderate
Description
If a domain name contained a RTL character, it would cause the domain to be rendered to the right of the path. This could lead to user confusion and spoofing attacks.
This bug only affects Firefox for Android. Other operating systems are unaffected.
Note: Due to a clerical error this advisory was not included in the original announcement, and was added in Feburary 2022.
References
#CVE-2021-38493: Memory safety bugs fixed in Firefox 92, Firefox ESR 78.14 and Firefox ESR 91.1
- Reporter
- Mozilla developers and community
- Impact
- high
Description
Mozilla developers Gabriele Svelto and Tyson Smith reported memory safety bugs present in Firefox 91 and Firefox ESR 78.13. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.
References
#CVE-2021-38494: Memory safety bugs fixed in Firefox 92
- Reporter
- Mozilla developers and community
- Impact
- high
Description
Mozilla developers Christian Holler and Lars T Hansen reported memory safety bugs present in Firefox 91. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code.