How severe is CVE-2015-4515?

CVE-2015-4515 has a CVSS 2.0 base score of 4.3, rated medium severity.

Is CVE-2015-4515 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-4515?

CVE-2015-4515 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2015-4515?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2015-4515 published?

CVE-2015-4515 was published on 2015-11-05 and last updated on 2026-06-17.

CVE-2015-4515

CVE-2015-4515 is a medium-severity vulnerability in Mozilla Firefox with a CVSS 2.0 base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-200.

Key facts

Severity: Medium (CVSS 2.0 base score 4.3)
EPSS exploit prediction: 2% (77th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Mozilla Firefox
Published: 2015-11-05
Last modified: 2026-06-17

Description

Mozilla Firefox before 42.0, when NTLM v1 is enabled for HTTP authentication, allows remote attackers to obtain sensitive hostname information by constructing a crafted web site that sends an NTLM request and reads the Workstation field of an NTLM type 3 message.

Frequently asked questions

What is CVE-2015-4515?: Mozilla Firefox before 42.0, when NTLM v1 is enabled for HTTP authentication, allows remote attackers to obtain sensitive hostname information by constructing a crafted web site that sends an NTLM request and reads the Workstation field of an NTLM type 3 message.
How severe is CVE-2015-4515?: CVE-2015-4515 has a CVSS 2.0 base score of 4.3, rated medium severity.
Is CVE-2015-4515 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (77th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-4515?: CVE-2015-4515 affects Mozilla Firefox. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2015-4515?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2015-4515 published?: CVE-2015-4515 was published on 2015-11-05 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

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