Exploited vulnerability · CISA KEV

Is CVE-2015-4495 exploited? Yes: in CISA KEV since 25 May 2022

Gociux · Mozilla Firefox · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2015-4495, Mozilla Firefox Security Feature Bypass Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 25 May 2022, 2482 days after it was published. It affects Mozilla Firefox. If you run it, CISA's required action is: Apply updates per vendor instructions.

exploitedYesCISA KEV · 25 May 2022

ransomwareNot knownno confirmed use

EPSStop 1%among the most likely CVEs to be exploited

severity8.8CVSS 3.1 · high

US federal due15 Jun 2022BOD 22-01 deadline

What it is

Moxilla Firefox allows remote attackers to bypass the Same Origin Policy to read arbitrary files or gain privileges.

Vendor	Mozilla (13 exploited CVEs in KEV)
Product	Firefox
Vulnerability	Mozilla Firefox Security Feature Bypass Vulnerability
Weakness	CWE-200
Published	8 Aug 2015
Added to KEV	25 May 2022
Reported by (CNA)	mozilla

What to do

Check whether you run it. Look for Firefox in your asset inventory, including appliances and cloud images. Stack check lists every exploited Mozilla CVE at once.
Apply the fix. Apply updates per vendor instructions.
If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 8 Aug 2015.
Get told next time. Email alerts when CISA adds a CVE for Mozilla.

Other exploited CVEs in Firefox

CVE-2024-9680: Mozilla Firefox Use-After-Free Vulnerability (15 Oct 2024)
CVE-2022-26486: Mozilla Firefox Use-After-Free Vulnerability (7 Mar 2022)
CVE-2022-26485: Mozilla Firefox Use-After-Free Vulnerability (7 Mar 2022)
CVE-2013-1675: Mozilla Firefox Information Disclosure Vulnerability (3 Mar 2022)

References

nvd.nist.gov/vuln/detail/CVE-2015-4495

Questions

Is CVE-2015-4495 being exploited?

Yes. CISA added CVE-2015-4495 to the Known Exploited Vulnerabilities catalog on 25 May 2022, which means there is reliable evidence of exploitation in the wild.

Is CVE-2015-4495 used in ransomware attacks?

CISA does not list known ransomware use for it. That can change, and exploitation alone is reason to fix it first.

How do I fix CVE-2015-4495?

Apply updates per vendor instructions. Check Mozilla's advisory for the fixed versions, and if you can't patch quickly, restrict access to the affected Firefox and watch it for signs of compromise.

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in May 2022 · Mozilla scorecard · act-now radar.

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