How severe is CVE-2009-0790?

CVE-2009-0790 has a CVSS 2.0 base score of 5.0, rated medium severity.

Is CVE-2009-0790 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2009-0790?

CVE-2009-0790 primarily affects Strongswan. In total, 60 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2009-0790?

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

When was CVE-2009-0790 published?

CVE-2009-0790 was published on 2009-04-01 and last updated on 2026-06-16.

CVE-2009-0790

CVE-2009-0790 is a medium-severity vulnerability in Strongswan 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% (87th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Strongswan
Published: 2009-04-01
Last modified: 2026-06-16

Description

The pluto IKE daemon in Openswan and Strongswan IPsec 2.6 before 2.6.21 and 2.4 before 2.4.14, and Strongswan 4.2 before 4.2.14 and 2.8 before 2.8.9, allows remote attackers to cause a denial of service (daemon crash and restart) via a crafted (1) R_U_THERE or (2) R_U_THERE_ACK Dead Peer Detection (DPD) IPsec IKE Notification message that triggers a NULL pointer dereference related to inconsistent ISAKMP state and the lack of a phase2 state association in DPD.

Frequently asked questions

What is CVE-2009-0790?: The pluto IKE daemon in Openswan and Strongswan IPsec 2.6 before 2.6.21 and 2.4 before 2.4.14, and Strongswan 4.2 before 4.2.14 and 2.8 before 2.8.9, allows remote attackers to cause a denial of service (daemon crash and restart) via a crafted (1) R_U_THERE or (2) R_U_THERE_ACK Dead Peer Detection (DPD) IPsec IKE Notification message that triggers a NULL pointer dereference related to inconsistent ISAKMP state and the lack of a phase2 state association in DPD.
How severe is CVE-2009-0790?: CVE-2009-0790 has a CVSS 2.0 base score of 5.0, rated medium severity.
Is CVE-2009-0790 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (87th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0790?: CVE-2009-0790 primarily affects Strongswan. In total, 60 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-0790?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-0790 published?: CVE-2009-0790 was published on 2009-04-01 and last updated on 2026-06-16.

References

Affected products (60)

cpe:2.3:a:strongswan:strongswan:2.4.0:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.4.0a:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.4.1:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.4.2:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.4.3:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.4.4:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.6.0:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.6.1:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.6.2:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.6.3:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.6.4:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.8.0:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.8.1:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.8.2:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.8.3:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.8.4:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.8.5:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.8.6:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.8.7:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:2.8.8:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.0:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.1:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.2:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.3:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.4:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.5:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.6:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.7:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.8:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.9:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.10:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.11:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.12:*:*:*:*:*:*:*
cpe:2.3:a:strongswan:strongswan:4.2.13:*:*:*:*:*:*:*
cpe:2.3:a:xelerance:openswan:2.4.0:*:*:*:*:*:*:*
cpe:2.3:a:xelerance:openswan:2.4.1:*:*:*:*:*:*:*
cpe:2.3:a:xelerance:openswan:2.4.2:*:*:*:*:*:*:*
cpe:2.3:a:xelerance:openswan:2.4.3:*:*:*:*:*:*:*
cpe:2.3:a:xelerance:openswan:2.4.4:*:*:*:*:*:*:*
cpe:2.3:a:xelerance:openswan:2.4.5:*:*:*:*:*:*:*

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