Security Vulnerabilities fixed in Firefox 121 — Mozilla

The WebGL DrawElementsInstanced method was susceptible to a heap buffer overflow when used on systems with the Mesa VM driver. This issue could allow an attacker to perform remote code execution and sandbox escape.
Multiple NSS NIST curves were susceptible to a side-channel attack known as “Minerva”. This attack could potentially allow an attacker to recover the private key.
EncryptingOutputStream was susceptible to exposing uninitialized data. This issue could only be abused in order to write data to a local disk which may have implications for private browsing mode.
When resolving a symlink, a race may occur where the buffer passed to readlink may actually be smaller than necessary. This bug only affects Firefox on Unix-based operating systems (Android, Linux, MacOS). Windows is unaffected.
Firefox was susceptible to a heap buffer overflow in nsTextFragment due to insufficient OOM handling.
A use-after-free condition affected TLS socket creation when under memory pressure.
TypedArrays can be fallible and lacked proper exception handling. This could lead to abuse in other APIs which expect TypedArrays to always succeed.
The VideoBridge allowed any content process to use textures produced by remote decoders. This could be abused to escape the sandbox.
The timing of a button click causing a popup to disappear was approximately the same length as the anti-clickjacking delay on permission prompts. It was possible to use this fact to surprise users by luring them to click where the permission grant button would be about to appear.
The nsWindow::PickerOpen(void) method was susceptible to a heap buffer overflow when running in headless mode.
In some instances, the user-agent would allow push requests which lacked a valid VAPID even though the push manager subscription defined one. This could allow empty messages to be sent from unauthorized parties.This bug only affects Firefox on Android.
A element could have been manipulated to paint content outside of a sandboxed iframe. This could allow untrusted content to display under the guise of trusted content.
Applications which spawn a Toast notification in a background thread may have obscured fullscreen notifications displayed by Firefox. This issue only affects Android versions of Firefox and Firefox Focus.
Under certain conditions, Firefox did not display a warning when a user attempted to navigate to a new protocol handler.
Browser tab titles were being leaked by GNOME to system logs. This could potentially expose the browsing habits of users running in a private tab.
The ShutdownObserver() was susceptible to potentially undefined behavior due to its reliance on a dynamic type that lacked a virtual destructor.
Memory safety bugs present in Firefox 120, Firefox ESR 115.5, and Thunderbird 115.5. 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.
Memory safety bugs present in Firefox 120. 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.