CVE-2017-9023: Strongswan

High severity, CVSS 7.5. EPSS: 2.2% chance of exploitation in the next 30 days.

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.

Affected products

• Strongswan Strongswan: up to and including 5.5.2

Published 2017-06-08. Last modified 2026-06-17.