What is CVE-2018-5381?

CVE-2018-5381 is a medium-severity vulnerability in Quagga Bgpd, classified under CWE-228. CVSS score: 6.5/10. Published 2018-02-19.

How severe is CVE-2018-5381?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Quagga Bgpd

CVE-2018-5381

The Quagga BGP daemon (bgpd) prior to version 1.2.3 has a bug in its parsing of "Capabilities" in BGP OPEN messages, in the bgp_packet.c:bgp_capability_msg_parse function. The parser can enter an infinite loop on invalid capabilities if a Multi-Protocol capability does not have a recognized AFI/SAFI, causing a denial of service.

Published 2018-02-19 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.302 (98.2th percentile), scored 2026-10-18.

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 98th percentile — 98.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.300 · newest: 0.302 · change: +0.002

Affected products

Quagga Bgpd — versions bpgd
Quagga
Siemens Ruggedcom Rox Ii
Siemens Ruggedcom Rox Ii Firmware
Canonical Ubuntu Linux — versions 14.04, 16.04, 17.10
Debian Linux — versions 7.0, 8.0, 9.0

Weakness classification (CWE)

References

gogs.quagga.net/Quagga/quagga/src/master/doc/security/Quagga-2018-1975.txt (Vendor Advisory)
usn.ubuntu.com/3573-1/ (vendor-advisory, Third Party Advisory)
www.debian.org/security/2018/dsa-4115 (vendor-advisory, Third Party Advisory)
savannah.nongnu.org/forum/forum.php (Third Party Advisory)
security.gentoo.org/glsa/201804-17 (vendor-advisory, Third Party Advisory)
lists.debian.org/debian-lts-announce/2018/02/msg00021.html (mailing-list, Mailing List, Third Party Advisory)
www.kb.cert.org/vuls/id/940439 (US Government Resource, Third Party Advisory, third-party-advisory)
cert-portal.siemens.com/productcert/pdf/ssa-451142.pdf (Third Party Advisory, Mitigation)

Frequently asked questions

What is CVE-2018-5381?: CVE-2018-5381 is a medium-severity vulnerability in Quagga Bgpd, classified under CWE-228. CVSS score: 6.5/10. Published 2018-02-19.
How severe is CVE-2018-5381?: Medium severity. CVSS v3 base score is 6.5 out of 10.