CVE-2016-5361
programs/pluto/ikev1.c in libreswan before 3.17 retransmits in initial-responder states, which...
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
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.
- Record
CVE-2016-5361- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Weakness
- CWE-20
- Updated
- 2026-11-02
CVE List No score
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.
- Record
CVE-2016-5361- Updated
- 2026-11-02
EUVDEUVD-2016-6312 No score
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.
- Record
EUVD-2016-6312- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-pvgh-6wjg-x887
programs/pluto/ikev1.c in libreswan before 3.17 retransmits in initial-responder states, which...
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.
- Record
GHSA-pvgh-6wjg-x887- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
OSV
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.
- Record
CVE-2016-5361- CVSS 3.0
- 7.5 High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libreswanRed Hat:enterprise_linux:7::client |
before 0:3.15-8.el7 | 0:3.15-8.el7 |
libreswan-debuginfoRed Hat:enterprise_linux:7::client |
before 0:3.15-8.el7 | 0:3.15-8.el7 |
libreswanRed Hat:enterprise_linux:7::server |
before 0:3.15-8.el7 | 0:3.15-8.el7 |
libreswan-debuginfoRed Hat:enterprise_linux:7::server |
before 0:3.15-8.el7 | 0:3.15-8.el7 |
libreswanRed Hat:enterprise_linux:7::workstation |
before 0:3.15-8.el7 | 0:3.15-8.el7 |
libreswan-debuginfoRed Hat:enterprise_linux:7::workstation |
before 0:3.15-8.el7 | 0:3.15-8.el7 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2016-5361 is a high vulnerability (CVSS 7.5) in Libreswan, published June 16, 2016. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.72%, the 86th percentile. Fixed in libreswan 0:3.15-8.el7.
References
lists.libreswan.org/pipermail/swan-dev/2016-March/001394.html
rhn.redhat.com/errata/RHSA-2016-2603.html
github.com/libreswan/libreswan/commit/152d6d95632d8b9477c170f1de99bcd86d7fb1d6
openwall.com/lists/oss-security/2016/06/10/4
nvd.nist.gov/vuln/detail/CVE-2016-5361
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access.redhat.com/errata/RHSA-2016:2603
kb.cert.org/vuls/id/419128
libreswan.org/security/CVE-2016-5361/CVE-2016-5361.txt
bugzilla.redhat.com/show_bug.cgi?id=1190526
security.access.redhat.com/data/csaf/v2/advisories/2016/rhsa-2016_2603.json
cve.org/CVERecord?id=CVE-2016-5361