How severe is CVE-2005-3671?

CVE-2005-3671 has a CVSS 2.0 base score of 7.8, rated high severity.

Is CVE-2005-3671 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (94th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2005-3671?

CVE-2005-3671 primarily affects Frees Wan. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2005-3671?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2005-3671 published?

CVE-2005-3671 was published on 2005-11-18 and last updated on 2026-06-16.

CVE-2005-3671

CVE-2005-3671 is a high-severity vulnerability in Frees Wan with a CVSS 2.0 base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 2.0 base score 7.8)
EPSS exploit prediction: 7% (94th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Frees Wan
Published: 2005-11-18
Last modified: 2026-06-16

Description

The Internet Key Exchange version 1 (IKEv1) implementation in Openswan 2 (openswan-2) before 2.4.4, and freeswan in SUSE LINUX 9.1 before 2.04_1.5.4-1.23, allow remote attackers to cause a denial of service via (1) a crafted packet using 3DES with an invalid key length, or (2) unspecified inputs when Aggressive Mode is enabled and the PSK is known, as demonstrated by the PROTOS ISAKMP Test Suite for IKEv1.

Frequently asked questions

What is CVE-2005-3671?: The Internet Key Exchange version 1 (IKEv1) implementation in Openswan 2 (openswan-2) before 2.4.4, and freeswan in SUSE LINUX 9.1 before 2.04_1.5.4-1.23, allow remote attackers to cause a denial of service via (1) a crafted packet using 3DES with an invalid key length, or (2) unspecified inputs when Aggressive Mode is enabled and the PSK is known, as demonstrated by the PROTOS ISAKMP Test Suite for IKEv1.
How severe is CVE-2005-3671?: CVE-2005-3671 has a CVSS 2.0 base score of 7.8, rated high severity.
Is CVE-2005-3671 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 7% (94th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2005-3671?: CVE-2005-3671 primarily affects Frees Wan. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2005-3671?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2005-3671 published?: CVE-2005-3671 was published on 2005-11-18 and last updated on 2026-06-16.

References

Affected products (9)

cpe:2.3:a:frees_wan:frees_wan:2.04:*:*:*:*:*:*:*
cpe:2.3:a:openswan:openswan:2.1.1:*:*:*:*:*:*:*
cpe:2.3:a:openswan:openswan:2.1.2:*:*:*:*:*:*:*
cpe:2.3:a:openswan:openswan:2.1.4:*:*:*:*:*:*:*
cpe:2.3:a:openswan:openswan:2.1.5:*:*:*:*:*:*:*
cpe:2.3:a:openswan:openswan:2.1.6:*:*:*:*:*:*:*
cpe:2.3:a:openswan:openswan:2.2:*:*:*:*:*:*:*
cpe:2.3:a:openswan:openswan:2.3:*:*:*:*:*:*:*
cpe:2.3:a:xelerance:openswan:2.4.0:*:*:*:*:*:*:*

More vulnerabilities in Frees Wan

CVE-2004-0590 — Critical (CVSS 10.0): FreeS/WAN 1.x and 2.x, and other related products including superfreeswan 1.x, openswan 1.x before 1.0.6, openswan 2.x…
CVE-2002-0666 — Medium (CVSS 5.0): IPSEC implementations including (1) FreeS/WAN and (2) KAME do not properly calculate the length of authentication data,…

All CVEs affecting Frees Wan →