CVE-2022-26485
Mozilla Firefox Use-After-Free Vulnerability
Description
CVE-2022-26485 is a high-severity use after free vulnerability affecting Mozilla Firefox. Mozilla Firefox contains a use-after-free vulnerability in XSLT parameter processing which can be exploited to perform arbitrary code execution. CISA has added this vulnerability to its Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. With an EPSS score of 5.34% (89.9th percentile), this vulnerability has a notable probability of exploitation.
KEV Information
CVSS Score
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HOpen in CalculatorAffected Products
| Vendor | Product | Version |
|---|---|---|
| mozilla | firefox | < 91.6.1; < 97.0.2 |
| mozilla | firefox focus | < 97.3.0 |
| mozilla | firefox mobile | < 97.3.0 |
| mozilla | thunderbird | < 91.6.2 |
Multiple CVSS Assessments
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=1758062(Exploit, Issue Tracking, Vendor Advisory)
- https://www.mozilla.org/security/advisories/mfsa2022-09/(Vendor Advisory)
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-26485(US Government Resource)
Weakness Type
CWE-416: Use After Free
Use After Free (UAF) is a vulnerability that occurs when software continues to use a pointer after the memory it references has been freed. Once memory is freed, it may be reallocated for other purposes.
Learn more: CWE-416 — Use After Free
Impact Analysis
CVE-2022-26485 carries a CVSS 3.1 score of 8.8 (HIGH), indicating a high-severity threat. The vulnerability is exploitable over the network with low attack complexity and requires no authentication, though user interaction is needed. Successful exploitation can severely compromise data confidentiality, and allow unauthorized modification of data and systems, and cause complete service disruption. Organizations running affected Firefox deployments face significant operational risk if this vulnerability remains unpatched.
Exploit Maturity
CVE-2022-26485 is confirmed as actively exploited through its listing in the CISA Known Exploited Vulnerabilities catalog. The EPSS score of 5.34% (89.9th percentile) indicates a measurable probability of exploitation. Public exploit code is available, which lowers the barrier for attackers and increases the urgency of remediation. Federal agencies were required to remediate this vulnerability by 2022-03-21 per CISA's binding operational directive.
Remediation
- Apply vendor patches immediately as mandated by CISA KEV: Apply updates per vendor instructions.
- Verify that all instances of affected products (mozilla firefox < 91.6.1; < 97.0.2; < 97.3.0; mozilla firefox focus < 97.3.0; mozilla thunderbird < 91.6.2) have been updated to patched versions.
- If immediate patching is not possible, restrict network access to affected systems using firewall rules and network segmentation to limit exposure.
- Monitor systems for indicators of compromise, including unusual process activity, unexpected network connections, and unauthorized configuration changes.
- Review security logs and conduct threat hunting to determine if the vulnerability was exploited prior to patching.
Technical Details
CVE-2022-26485 affects Mozilla Firefox. Mozilla Firefox contains a use-after-free vulnerability in XSLT parameter processing which can be exploited to perform arbitrary code execution. The attack vector is network-based, meaning an attacker can exploit this vulnerability remotely without physical access to the target system. The CVSS score of 8.8 reflects a serious vulnerability that poses meaningful risk to affected environments.
Frequently Asked Questions
Is CVE-2022-26485 being actively exploited?
Yes. CVE-2022-26485 is listed in the CISA Known Exploited Vulnerabilities catalog, confirming active exploitation. The EPSS score of 5.34% (89.9th percentile) further indicates a measurable exploitation probability.
What products are affected by CVE-2022-26485?
CVE-2022-26485 affects Mozilla Firefox. Specifically affected products include: mozilla firefox (< 91.6.1; < 97.0.2; < 97.3.0), mozilla firefox focus (< 97.3.0), mozilla thunderbird (< 91.6.2).
How do I fix CVE-2022-26485?
Apply updates per vendor instructions. Ensure all affected systems are updated to the latest patched versions. If patching is not immediately possible, implement network-level mitigations to limit exposure.
How severe is CVE-2022-26485?
CVE-2022-26485 has a CVSS 3.1 score of 8.8 (HIGH). This is a high-severity vulnerability that should be prioritized for remediation.
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