A team of Mozilla developers, including Calixte Denizet, Kershaw Chang, Christian Holler, Jason Kratzer, Gabriele Svelto, Tyson Smith, Simon Giesecke, and Steve Fink, has reported a critical vulnerability in the form of memory safety bugs present in Firefox 95 and Firefox ESR 91.4. These bugs, identified as CVE-2022-22751, demonstrate evidence of memory corruption that could potentially be exploited by attackers to execute arbitrary code. The affected versions of the software include Firefox ESR < 91.5, Firefox < 96, and Thunderbird < 91.5. In this post, we will take a closer look at the exploit details, corresponding patches, and best practices to protect your systems against this vulnerability.

Exploit Details

The developers identified a series of memory safety bugs in Firefox and related software components, which may perform unexpected actions due to the presence of wrong or unanticipated data within a specific memory location. When these memory safety bugs are triggered, they can potentially result in memory corruption, which allows attackers to manipulate the data within those memory sections and subsequently execute arbitrary code.

// Example of a vulnerable code snippet
void vulnerable_function(char *input) {
    char buf[100];
    strcpy(buf, input);

int main(int argc, char *argv[]) {
    return ;

In the code snippet above, the vulnerable_function() is prone to memory corruption due to an unchecked buffer. An attacker could exploit this vulnerability by providing a specifically crafted input to cause the buffer overflow, leading to memory corruption, and ultimately executing arbitrary code.

Original References

- Mozilla Foundation Security Advisory 2022-01: https://www.mozilla.org/en-US/security/advisories/mfsa2022-01/
- Mozilla's Security Bug Tracker: https://bugzilla.mozilla.org/show_bug.cgi?id=CVE-2022-22751

The Mozilla developers' public disclosure of this vulnerability provides a detailed account of their findings and serves as critical resources for understanding the potential impact and scope of this issue.

Patch and Mitigation

In order to address the CVE-2022-22751 vulnerability, Mozilla has rolled out updates for its affected software:

1. Firefox 96: https://www.mozilla.org/en-US/firefox/96./releasenotes/
2. Firefox ESR 91.5: https://www.mozilla.org/en-US/firefox/91.5.esr/releasenotes/
3. Thunderbird 91.5: https://www.mozilla.org/en-US/thunderbird/91.5./releasenotes/

Users and administrators are advised to update their software to the latest versions immediately to protect their systems from potential exploitation. The updates address the memory safety bugs and contain additional security fixes to ensure system protection.

CVE-2022-22751 emphasizes the importance of

- Regularly updating software – Updates often include security patches and mitigations against recent vulnerabilities.
- Staying informed about recently discovered security issues – Subscribe to security bulletins, newsletters, or other reliable sources to remain updated on potential threats.
- Reporting any discovered vulnerabilities – If you come across a potential security bug or vulnerability, report it to the appropriate organization (in this case, Mozilla) for evaluation and fixing.

Being proactive and ensuring that your software is up-to-date and secure is crucial in preventing attackers from exploiting vulnerabilities such as CVE-2022-22751. Stay vigilant and keep your systems protected.


Published on: 12/22/2022 20:15:00 UTC
Last modified on: 12/29/2022 22:55:00 UTC