Rsync < 3.4.3 Authorization Bypass via Hostname Resolution (RsyncProject rsync)

CVE-2026-43617
MEDIUM 6.3

At a glance

Source
NVD
EPSS
EPSS 0.28 % · percentile 21 ()
State
PUBLISHED
Published
Updated
Assigner
VulnCheck
NVD status
Analyzed

Description

Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.

Weaknesses (CWE)

  • CWE-289 — Authentication Bypass by Alternate Name

References

Scores

VersionScoreVectorScored by
CVSS 4.0MEDIUM 6.3CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:NVulnCheck
CVSS 3.1MEDIUM 4.8CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:NVulnCheck
CVSS 4.0MEDIUM 6.3CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XNVD · disclosure@vulncheck.com (Secondary)
CVSS 3.1MEDIUM 4.8CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:NNVD · disclosure@vulncheck.com (Secondary)

European references

Affected configurations (NVD CPE)

Affected products

ProductVersions
RsyncProject · rsyncaffected 0 < 3.4.3

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD