Is CVE-2017-9023 in the CISA KEV catalog?

No. CVE-2017-9023 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2017-9023?

CVE-2017-9023 has a CVSS v3 base score of 7.5 (HIGH).

What is the EPSS score for CVE-2017-9023?

CVE-2017-9023 has an EPSS score of 2.22% (81th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2017-9023?

Upgrade strongswan on debian 11 to 5.5.1-4 or later. Fixes are available for 4 affected products.

CVE & CISA-KEV Catalog

CVE-2017-9023

HIGHEPSS 81th pctl

7.5

CVSS v3

NVD

Description

The ASN.1 parser in strongSwan before 5.5.3 improperly handles CHOICE types when the x509 plugin is enabled, which allows remote attackers to cause a denial of service (infinite loop) via a crafted certificate.

CWE-835

How to fix

Remediation Available

strongswanDebian

Fixed in:5.5.1-4CVE-2017-9023

libstrongswanUbuntu

Fixed in:5.1.2-0ubuntu2.6USN-3301-1

Fixed in:5.3.5-1ubuntu3.3USN-3301-1

strongswanUbuntu

Fixed in:5.1.2-0ubuntu2.6USN-3301-1

Fixed in:5.3.5-1ubuntu3.3USN-3301-1

strongswan-plugin-gmpUbuntu

Fixed in:5.1.2-0ubuntu2.6USN-3301-1

Fixed in:5.3.5-1ubuntu3.3USN-3301-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploit Intelligence

2.22%probability of exploitation in 30 days

81stpercentile

Elevated risk: more likely to be exploited than 81% of all known CVEs.

References

Third-Party Advisory3

Other references1

strongswan.org

Related Vulnerabilities

Other CWE-835 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-13935	High	7.5	88%	-	Fix
CVE-2020-36227	High	7.5	78%	-	Fix
CVE-2022-0778	High	7.5	71%	-	Fix
CVE-2019-14241	High	7.5	70%	-	-
CVE-2017-16944	High	7.5	63%	-	Fix
CVE-2024-20353	High	8.6	63%	KEV	-

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-13.