rsync: Six Flaws Incl. Daemon Heap Overflow (CVE-2024-12084)
Distros shipped fixes in January 2025 and there is no known exploitation, but internet-facing rsync daemons have since needed two more security releases, so verify you run a current rsync rather than just 3.4.0.
Must act: Operators of rsync daemons (rsyncd, TCP 873), especially public mirrors with anonymous read access, and anyone who pulls from untrusted rsync servers.
Can relax: Hosts that only use rsync over SSH between machines you control, with distro-patched packages, face little practical risk from this set.
- Check versions with rsync --version (3.4.0+ reports protocol version 32) or your package manager, on servers, containers and appliances.
- Update to your distro's patched rsync package, or upstream 3.5.1, which also includes the later 2026 security releases.
- If a daemon cannot be updated immediately, rebuild with -DDISABLE_SHA512_DIGEST and -DDISABLE_SHA256_DIGEST (mitigates CVE-2024-12084) and -ftrivial-auto-var-init=zero (CVE-2024-12085), or firewall TCP 873 to trusted clients.