Mozilla Foundation Security Advisory 2021-04
Security Vulnerabilities fixed in Firefox ESR 78.7
- Announced
- January 26, 2021
- Impact
- high
- Products
- Firefox ESR
- Fixed in
-
- Firefox ESR 78.7
#CVE-2021-23953: Cross-origin information leakage via redirected PDF requests
- Reporter
- Rob Wu
- Impact
- high
Description
If a user clicked into a specifically crafted PDF, the PDF reader could be confused into leaking cross-origin information, when said information is served as chunked data.
References
#CVE-2021-23954: Type confusion when using logical assignment operators in JavaScript switch statements
- Reporter
- Gary Kwong
- Impact
- high
Description
Using the new logical assignment operators in a JavaScript switch statement could have caused a type confusion, leading to a memory corruption and a potentially exploitable crash.
References
#CVE-2020-26976: HTTPS pages could have been intercepted by a registered service worker when they should not have been
- Reporter
- Andrew Sutherland
- Impact
- moderate
Description
When a HTTPS page was embedded in a HTTP page, and there was a service worker registered for the former, the service worker could have intercepted the request for the secure page despite the iframe not being a secure context due to the (insecure) framing.
References
#CVE-2021-23960: Use-after-poison for incorrectly redeclared JavaScript variables during GC
- Reporter
- Irvan Kurniawan
- Impact
- moderate
Description
Performing garbage collection on re-declared JavaScript variables resulted in a user-after-poison, and a potentially exploitable crash.
References
#CVE-2021-23964: Memory safety bugs fixed in Firefox 85 and Firefox ESR 78.7
- Reporter
- Mozilla developers and community
- Impact
- high
Description
Mozilla developers Alexis Beingessner, Christian Holler, Andrew McCreight, Tyson Smith, Jon Coppeard, André Bargull, Jason Kratzer, Jesse Schwartzentruber, Steve Fink, Byron Campen reported memory safety bugs present in Firefox 84 and Firefox ESR 78.6. 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.