A heap-based buffer overflow was found in Corosync's Totem Process Group (totempg) message reassembly. When processing fragmented multicast messages, the buffer used to reassemble fragments lacks a runtime bounds check in release builds. A network-adjacent attacker able to send crafted multicast protocol messages to the cluster could cause a heap buffer overflow with attacker-controlled data. This can crash the Corosync daemon, causing a denial of service to the entire cluster, and may potentially allow further exploitation given sufficient heap-corruption control.
Exploitability
AV:AAC:HPR:NUI:NScope
S:UImpact
C:HI:HA:H7.5/CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HOther