The Linux kernel, versions 3.9+, is vulnerable to a denial of service attack with low rates of specially modified packets targeting IP fragment re-assembly. An attacker may cause a denial of service condition by sending specially crafted IP fragments. Various vulnerabilities in IP fragmentation have been discovered and fixed over the years. The current vulnerability (CVE-2018-5391) became exploitable in the Linux kernel with the increase of the IP fragment reassembly queue size.

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.

The Quagga BGP daemon (bgpd) prior to version 1.2.3 can overrun internal BGP code-to-string conversion tables used for debug by 1 pointer value, based on input.

The Quagga BGP daemon (bgpd) prior to version 1.2.3 can double-free memory when processing certain forms of UPDATE message, containing cluster-list and/or unknown attributes. A successful attack could cause a denial of service or potentially allow an attacker to execute arbitrary code.