The ASN.1 parser in strongSwan before 5.5.3 improperly handles CHOICE types when the x509…
Priority MEDIUM 43CWE-835Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Will not fix Red Hat: no fix planned
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-835.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.02222 82nd percentileScored 2026-11-07
Fix Will not fix Red Hat: no fix planned
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:strongswan:strongswan:*:*:*:*:*:*:*:* | up to 5.5.2 | Vulnerable | strongSwan |
- cpe:2.3:a:strongswan:strongswan:*:*:*:*:*:*:*:* Versions up to 5.5.2 Vulnerable ·strongSwan
Remediation
No fixed version listed by the sources yet.
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Will not fix |
Timeline
- 2026-10-02 Threatist record created from CVE-2017-9023
- 2026-10-03 Alias added: GHSA-3vpr-mhgf-fgjv
References
More Strongswan vulnerabilities
- TI-2023-22300 strongSwan before 5.9.12 has a buffer overflow and possible unauthenticated remote code… CVSS 3.1CRITICAL 9.8
- TI-2015-03374 strongSwan 5.2.2 and 5.3.0 allows remote attackers to cause a denial of service (daemon… CVSS 3.0CRITICAL 9.8
- TI-2004-00531 FreeS/WAN 1.x and 2.x, and other related products including superfreeswan 1.x, openswan… CVSS 2.0HIGH 10.0
- TI-2023-11610 strongSwan 5.9.8 and 5.9.9 potentially allows remote code execution because it uses a… CVSS 3.1CRITICAL 9.8
- TI-2021-20414 In strongSwan before 5.9.5, a malicious responder can send an EAP-Success message too… CVSS 3.1CRITICAL 9.1
- TI-2017-08240 The gmp plugin in strongSwan before 5.6.0 allows remote attackers to cause a denial of… CVSS 3.1HIGH 7.5
Sources
- CVE-2017-9023 · CVE Program
- CVE-2017-9023 · NVD
- FIRST EPSS
- GHSA-3vpr-mhgf-fgjv · GitHub Advisory Database · CC BY 4.0
- CVE-2017-9023 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences