Mozilla Foundation Security Advisory 2021-52
Security Vulnerabilities fixed in Firefox 95
- 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
#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
#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
#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
#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
#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
#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
#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
#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
#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
#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
#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
#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.