programs/pluto/ikev1.c in libreswan before 3.17 retransmits in initial-responder states…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 3 fixed, 2 without a fix
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and Red Hat.
Summary
programs/pluto/ikev1.c in libreswan before 3.17 retransmits in initial-responder states, which allows remote attackers to cause a denial of service (traffic amplification) via a spoofed UDP packet. NOTE: the original behavior complies with the IKEv1 protocol, but has a required security update from the libreswan vendor; as of 2016-06-10, it is expected that several other IKEv1 implementations will have vendor-required security updates, with separate CVE IDs assigned to each.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
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:libreswan:libreswan:*:*:*:*:*:*:*:* | up to 3.16 | Vulnerable | The Libreswan Project |
- cpe:2.3:a:libreswan:libreswan:*:*:*:*:*:*:*:* Versions up to 3.16 Vulnerable ·The Libreswan Project
Remediation
Red Hat 1 advisory
- RHSA-2016:2603 Released 2016-11-03 · Red Hat rating Moderatelibreswan security and bug fix update
- Red Hat Enterprise Linux Client (v. 7) libreswan-3.15-8.el7
- Red Hat Enterprise Linux Server (v. 7) libreswan-3.15-8.el7
- Red Hat Enterprise Linux Workstation (v. 7) libreswan-3.15-8.el7
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 5 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux Client (v. 7) | Fixed | RHSA-2016:2603 |
| Red Hat Enterprise Linux Server (v. 7) | Fixed | RHSA-2016:2603 |
| Red Hat Enterprise Linux Workstation (v. 7) | Fixed | RHSA-2016:2603 |
Timeline
- 2026-10-02 Threatist record created from CVE-2016-5361
- 2026-10-03 Alias added: GHSA-pvgh-6wjg-x887
References
Advisory 1
More The Libreswan Project Libreswan vulnerabilities
- TI-2023-09114 Libreswan 4.9 allows remote attackers to cause a denial of service (assert failure and… CVSS 3.1MEDIUM 6.5
- TI-2013-05949 Race condition in the libreswan.spec files for Red Hat Enterprise Linux (RHEL) and Fedora… CVSS 2.0HIGH 9.3
- TI-2023-02152 Uncontrolled resource consumption in libreswan CVSS 3.1HIGH 7.5
- TI-2026-37395 IKEv2 Denial of Service via RSA-SHA1 (PKCS#1 RSASSA-PKCS1-v1_5) authentication payload CVSS 3.1HIGH 8.1
- TI-2026-37394 IKEv1 Denial of Service via RSA-SHA1 (PKCS#1 Version 1.5 Encrypted) authentication payload CVSS 3.1HIGH 8.1
- TI-2023-14401 pluto in Libreswan before 4.11 allows a denial of service (responder SPI mishandling and… CVSS 3.1HIGH 7.5
Sources
- CVE-2016-5361 · CVE Program
- CVE-2016-5361 · NVD
- FIRST EPSS
- GHSA-pvgh-6wjg-x887 · GitHub Advisory Database · CC BY 4.0
- CVE-2016-5361 · 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