[MFSA-2023-56] Security Vulnerabilities fixed in Firefox 121

CVE-2023-6135: NSS susceptible to "Minerva" attack (high)
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.

CVE-2023-6856: Heap-buffer-overflow affecting WebGL DrawElementsInstanced method with Mesa VM driver (high)
The WebGL <code>DrawElementsInstanced</code> 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.

CVE-2023-6857: Symlinks may resolve to smaller than expected buffers (moderate)
When resolving a symlink, a race may occur where the buffer passed to <code>readlink</code> may actually be smaller than necessary.
This bug only affects Firefox on Unix-based operating systems (Android, Linux, MacOS). Windows is unaffected.

CVE-2023-6858: Heap buffer overflow in nsTextFragment (moderate)
Firefox was susceptible to a heap buffer overflow in <code>nsTextFragment</code> due to insufficient OOM handling.

CVE-2023-6859: Use-after-free in PR_GetIdentitiesLayer (moderate)
A use-after-free condition affected TLS socket creation when under memory pressure.

CVE-2023-6860: Potential sandbox escape due to VideoBridge lack of texture validation (moderate)
The <code>VideoBridge</code> allowed any content process to use textures produced by remote decoders. This could be abused to escape the sandbox.

CVE-2023-6861: Heap buffer overflow affected nsWindow::PickerOpen(void) in headless mode (moderate)
The <code>nsWindow::PickerOpen(void)</code> method was susceptible to a heap buffer overflow when running in headless mode.

CVE-2023-6863: Undefined behavior in ShutdownObserver() (low)
The <code>ShutdownObserver()</code> was susceptible to potentially undefined behavior due to its reliance on a dynamic type that lacked a virtual destructor.

CVE-2023-6864: Memory safety bugs fixed in Firefox 121, Firefox ESR 115.6, and Thunderbird 115.6 (high)
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.

CVE-2023-6865: Potential exposure of uninitialized data in EncryptingOutputStream (high)
<code>EncryptingOutputStream</code> 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.

CVE-2023-6866: TypedArrays lack sufficient exception handling (moderate)
TypedArrays can be fallible and lacked proper exception handling. This could lead to abuse in other APIs which expect TypedArrays to always succeed.

CVE-2023-6867: Clickjacking permission prompts using the popup transition (moderate)
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.

CVE-2023-6868: WebPush requests on Firefox for Android did not require VAPID key (moderate)
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.

CVE-2023-6869: Content can paint outside of sandboxed iframe (low)
A <code><dialog></code> 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.

CVE-2023-6870: Android Toast notifications may obscure fullscreen event notifications (low)
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.

CVE-2023-6871: Lack of protocol handler warning in some instances (low)
Under certain conditions, Firefox did not display a warning when a user attempted to navigate to a new protocol handler.

CVE-2023-6872: Browsing history leaked to syslogs via GNOME (low)
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.

CVE-2023-6873: Memory safety bugs fixed in Firefox 121 (high)
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.