CVE-2024-12086: Rsync: rsync server leaks arbitrary client files

Severity: medium (CVSS 6.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.8% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-01-14 · updated 2026-08-21
Weakness: CWE-390

Description

A flaw was found in rsync. It could allow a server to enumerate the contents of an arbitrary file from the client's machine. This issue occurs when files are being copied from a client to a server. During this process, the rsync server will send checksums of local data to the client to compare with in order to determine what data needs to be sent to the server. By sending specially constructed checksum values for arbitrary files, an attacker may be able to reconstruct the data of those files byte-by-byte based on the responses from the client.

Affected products

Almalinux: 8.0, 9.0, 10.0
Archlinux Arch Linux: all versions
gentoo Linux: all versions
Nixos: before 24.11 — fixed in 24.11
Red Hat Enterprise Linux: 6.0, 7.0, 8.0, 9.0, 10.0
Red Hat OpenShift Container Platform 4.18: 4.0
RsyncProject rsync: through 3.3.0
Suse Linux: all versions
Tritondatacenter Smartos: before 20250123 — fixed in 20250123

How to fix

Upgrade to a fixed version: Nixos 24.11; Tritondatacenter Smartos 20250123. Check the vendor advisory for mitigations.

References

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