Headline
CVE-2021-43542: Security Vulnerabilities fixed in Firefox 95
Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.
Mozilla Foundation Security Advisory 2021-52
Announced
December 7, 2021
Impact
high
Products
Firefox
Fixed in
- Firefox 95
#CVE-2021-43536: URL leakage when navigating while executing asynchronous function
Reporter
Sunwoo Kim and Youngmin Kim of SNU CompSec Lab
Impact
high
Description
Under certain circumstances, asynchronous functions could have caused a navigation to fail but expose the target URL.
References
- Bug 1730120
#CVE-2021-43537: Heap buffer overflow when using structured clone
Reporter
bo13oy of Cyber Kunlun Lab
Impact
high
Description
An incorrect type conversion of sizes from 64bit to 32bit integers allowed an attacker to corrupt memory leading to a potentially exploitable crash.
References
- Bug 1738237
#CVE-2021-43538: Missing fullscreen and pointer lock notification when requesting both
Reporter
Irvan Kurniawan (@sourc7)
Impact
high
Description
By misusing a race in our notification code, an attacker could have forcefully hidden the notification for pages that had received full screen and pointer lock access, which could have been used for spoofing attacks.
References
- Bug 1739091
#CVE-2021-43539: GC rooting failure when calling wasm instance methods
Reporter
Asumu Takikawa and Ioanna Dimitriou
Impact
high
Description
Failure to correctly record the location of live pointers across wasm instance calls resulted in a GC occurring within the call not tracing those live pointers. This could have led to a use-after-free causing a potentially exploitable crash.
References
- Bug 1739683
#CVE-2021-4128: Use-after-free in fullscreen objects on MacOS
Reporter
Atila Butkovits
Impact
high
Description
When transitioning in and out of fullscreen mode, a graphics object was not correctly protected; resulting in memory corruption and a potentially exploitable crash.
This bug only affects Firefox on MacOS. Other operating systems are unaffected.
References
- Bug 1735852
#CVE-2021-43540: WebExtensions could have installed persistent ServiceWorkers
Reporter
Jake Heath
Impact
moderate
Description
WebExtensions with the correct permissions were able to create and install ServiceWorkers for third-party websites that would not have been uninstalled with the extension.
References
- Bug 1636629
#CVE-2021-43541: External protocol handler parameters were unescaped
Reporter
chriscla
Impact
moderate
Description
When invoking protocol handlers for external protocols, a supplied parameter URL containing spaces was not properly escaped.
References
- Bug 1696685
#CVE-2021-43542: XMLHttpRequest error codes could have leaked the existence of an external protocol handler
Reporter
Raphael Smolik
Impact
moderate
Description
Using XMLHttpRequest, an attacker could have identified installed applications by probing error messages for loading external protocols.
References
- Bug 1723281
#CVE-2021-43543: Bypass of CSP sandbox directive when embedding
Reporter
Armin Ebert
Impact
moderate
Description
Documents loaded with the CSP sandbox directive could have escaped the sandbox’s script restriction by embedding additional content.
References
- Bug 1738418
#CVE-2021-43544: Receiving a malicious URL as text through a SEND intent could have led to XSS
Reporter
Irwan
Impact
moderate
Description
When receiving a URL through a SEND intent, Firefox would have searched for the text, but subsequent usages of the address bar might have caused the URL to load unintentionally, which could lead to XSS and spoofing attacks.
This bug only affects Firefox for Android. Other operating systems are unaffected.
References
- Bug 1739934
#CVE-2021-43545: Denial of Service when using the Location API in a loop
Reporter
Paul Zühlcke
Impact
low
Description
Using the Location API in a loop could have caused severe application hangs and crashes.
References
- Bug 1720926
#CVE-2021-43546: Cursor spoofing could overlay user interface when native cursor is zoomed
Reporter
Daniel Veditz
Impact
low
Description
It was possible to recreate previous cursor spoofing attacks against users with a zoomed native cursor.
References
- Bug 1737751
#CVE-2021-4129: Memory safety bugs fixed in Firefox 95 and Firefox ESR 91.4
Reporter
Mozilla developers and community
Impact
high
Description
Mozilla developers and community members Julian Hector, Randell Jesup, Gabriele Svelto, Tyson Smith, Christian Holler, and Masayuki Nakano reported memory safety bugs present in Firefox 94. 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
- Memory safety bugs fixed in Firefox 95
Related news
Mozilla developers and community members Julian Hector, Randell Jesup, Gabriele Svelto, Tyson Smith, Christian Holler, and Masayuki Nakano reported memory safety bugs present in Firefox 94. 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. This vulnerability affects Firefox < 95, Firefox ESR < 91.4.0, and Thunderbird < 91.4.0.
Gentoo Linux Security Advisory 202208-14 - Multiple vulnerabilities have been found in Mozilla Thunderbird, the worst of which could result in the arbitrary execution of code. Versions less than 91.12.0 are affected.
Gentoo Linux Security Advisory 202208-14 - Multiple vulnerabilities have been found in Mozilla Thunderbird, the worst of which could result in the arbitrary execution of code. Versions less than 91.12.0 are affected.
Gentoo Linux Security Advisory 202208-14 - Multiple vulnerabilities have been found in Mozilla Thunderbird, the worst of which could result in the arbitrary execution of code. Versions less than 91.12.0 are affected.
Gentoo Linux Security Advisory 202208-14 - Multiple vulnerabilities have been found in Mozilla Thunderbird, the worst of which could result in the arbitrary execution of code. Versions less than 91.12.0 are affected.
Gentoo Linux Security Advisory 202208-14 - Multiple vulnerabilities have been found in Mozilla Thunderbird, the worst of which could result in the arbitrary execution of code. Versions less than 91.12.0 are affected.
Gentoo Linux Security Advisory 202208-14 - Multiple vulnerabilities have been found in Mozilla Thunderbird, the worst of which could result in the arbitrary execution of code. Versions less than 91.12.0 are affected.
Gentoo Linux Security Advisory 202208-14 - Multiple vulnerabilities have been found in Mozilla Thunderbird, the worst of which could result in the arbitrary execution of code. Versions less than 91.12.0 are affected.
Gentoo Linux Security Advisory 202208-14 - Multiple vulnerabilities have been found in Mozilla Thunderbird, the worst of which could result in the arbitrary execution of code. Versions less than 91.12.0 are affected.
Gentoo Linux Security Advisory 202208-14 - Multiple vulnerabilities have been found in Mozilla Thunderbird, the worst of which could result in the arbitrary execution of code. Versions less than 91.12.0 are affected.
Gentoo Linux Security Advisory 202208-14 - Multiple vulnerabilities have been found in Mozilla Thunderbird, the worst of which could result in the arbitrary execution of code. Versions less than 91.12.0 are affected.
Thunderbird unexpectedly enabled JavaScript in the composition area. The JavaScript execution context was limited to this area and did not receive chrome-level privileges, but could be used as a stepping stone to further an attack with other vulnerabilities. This vulnerability affects Thunderbird < 91.4.0.
When invoking protocol handlers for external protocols, a supplied parameter URL containing spaces was not properly escaped. This vulnerability affects Thunderbird < 91.4.0, Firefox ESR < 91.4.0, and Firefox < 95.