How severe is CVE-2015-3204?

CVE-2015-3204 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2015-3204 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-3204?

CVE-2015-3204 primarily affects Libreswan. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-3204?

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

When was CVE-2015-3204 published?

CVE-2015-3204 was published on 2015-07-01 and last updated on 2026-06-17.

CVE-2015-3204

CVE-2015-3204 is a medium-severity vulnerability in Libreswan with a CVSS 2.0 base score of 5.0. 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-20.

Key facts

Severity: Medium (CVSS 2.0 base score 5.0)
EPSS exploit prediction: 3% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Libreswan
Published: 2015-07-01
Last modified: 2026-06-17

Description

libreswan 3.9 through 3.12 allows remote attackers to cause a denial of service (daemon restart) via an IKEv1 packet with (1) unassigned bits set in the IPSEC DOI value or (2) the next payload value set to ISAKMP_NEXT_SAK.

Frequently asked questions

What is CVE-2015-3204?: libreswan 3.9 through 3.12 allows remote attackers to cause a denial of service (daemon restart) via an IKEv1 packet with (1) unassigned bits set in the IPSEC DOI value or (2) the next payload value set to ISAKMP_NEXT_SAK.
How severe is CVE-2015-3204?: CVE-2015-3204 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2015-3204 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-3204?: CVE-2015-3204 primarily affects Libreswan. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-3204?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2015-3204 published?: CVE-2015-3204 was published on 2015-07-01 and last updated on 2026-06-17.

References

Affected products (4)

cpe:2.3:a:libreswan:libreswan:3.9:*:*:*:*:*:*:*
cpe:2.3:a:libreswan:libreswan:3.10:*:*:*:*:*:*:*
cpe:2.3:a:libreswan:libreswan:3.11:*:*:*:*:*:*:*
cpe:2.3:a:libreswan:libreswan:3.12:*:*:*:*:*:*:*

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