CVE-2018-5381: Canonical Ubuntu Linux

High severity, CVSS 7.5. EPSS: 30.2% chance of exploitation in the next 30 days.

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.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only; version 17.10 only
• Debian Debian Linux: version 7.0 only; version 8.0 only; version 9.0 only
• Quagga Quagga: up to and including 1.2.2
• Siemens Ruggedcom Rox Ii Firmware: before 2.13.0 (fixed in 2.13.0)

Published 2018-02-19. Last modified 2026-06-17.