Severity by source
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/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:X
Primary rating from Vendor (VulnCheck).
CVSS VectorVendor: VulnCheck
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/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:X
Lifecycle Timeline
4DescriptionCVE.org
Rsync versions before 3.4.3 contain an off-by-one out-of-bounds stack write vulnerability in the establish_proxy_connection() function in socket.c that allows network attackers to corrupt stack memory by sending a malformed HTTP proxy response. Attackers can exploit this by positioning themselves between the client and proxy or controlling the proxy server to send a response line of 1023 or more bytes without a newline terminator, causing a null byte to be written to an out-of-bounds stack address when the RSYNC_PROXY environment variable is set.
AnalysisAI
Stack memory corruption in rsync before 3.4.3 allows network-positioned attackers to write a null byte past the end of a fixed-size stack buffer in the establish_proxy_connection() function in socket.c. The vulnerability is only reachable when the RSYNC_PROXY environment variable is set and an attacker controls or intercepts traffic to the configured HTTP proxy. Impact is constrained to a low-severity availability disruption (process crash) with no confidentiality or integrity exposure; no public exploit has been identified at time of analysis.
Technical ContextAI
The root cause is CWE-193 (Off-by-One Error) in the establish_proxy_connection() function in socket.c. The function reads an HTTP CONNECT proxy response into a fixed 1024-byte stack buffer but does not account for the null terminator when checking the response length boundary. When the proxy returns a response line of 1023 or more bytes without a newline, the code writes a null byte to an address one position beyond the buffer's end, corrupting adjacent stack memory. This code path is only invoked when the RSYNC_PROXY environment variable is configured, directing rsync to tunnel connections through an HTTP CONNECT proxy. CPE cpe:2.3:a:rsyncproject:rsync:*:*:*:*:*:*:*:* confirms all rsync versions prior to 3.4.3 carry the vulnerable code.
RemediationAI
Upgrade rsync to version 3.4.3, which includes the combined security fixes released by the RsyncProject team. The patched release is available at https://github.com/RsyncProject/rsync/releases/tag/v3.4.3 and the authoritative advisory is at https://github.com/RsyncProject/rsync/security/advisories/GHSA-8f85-j2cv-59m8. For environments that cannot upgrade immediately, the most effective compensating control is to unset the RSYNC_PROXY environment variable from all rsync invocations and system-level environments (e.g., /etc/environment, systemd unit files, cron job wrappers). Because the vulnerable code path in establish_proxy_connection() is only reachable when RSYNC_PROXY is defined, removing this variable completely eliminates the attack surface with no functional impact for deployments that do not rely on HTTP proxy tunneling for rsync. Organizations using rsync through an HTTP proxy should also audit whether the proxy endpoint is exposed to untrusted network positions.
A flaw was found in rsync which could be triggered when rsync compares file checksums. Rated high severity (CVSS 7.5), t
A heap-based buffer overflow flaw was found in the rsync daemon. Rated critical severity (CVSS 9.8), this vulnerability
rsync 3.1.1 allows remote attackers to write to arbitrary files via a symlink attack on a file in the synchronization pa
Server-to-client path traversal in rsync lets a malicious or compromised rsync server write files outside the client's i
An issue was discovered in rsync before 3.2.5 that allows malicious remote servers to write arbitrary files inside the d
The check_secret function in authenticate.c in rsync 3.1.0 and earlier allows remote attackers to cause a denial of serv
A flaw was found in rsync. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authenticati
The receive_xattr function in xattrs.c in rsync 3.1.2 and 3.1.3-development does not check for a trailing '\0' character
The daemon in rsync 3.1.2, and 3.1.3-development before 2017-12-03, does not check for fnamecmp filenames in the daemon_
rsync 3.1.3-development before 2017-10-24 mishandles archaic checksums, which makes it easier for remote attackers to by
Arbitrary file write outside the intended destination in rsync's client-side `--safe-links` handling allows a malicious
Receiver-side use-after-free in rsync 3.0.1 through 3.4.1 lets a malicious peer corrupt memory on a host running rsync w
Same weakness CWE-193 – Off-by-one Error
View allSame technique Buffer Overflow
View allVendor StatusVendor
SUSE
Severity: Medium| Product | Status |
|---|---|
| SUSE Linux Enterprise Desktop 15 SP7 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP7 | Fixed |
| SUSE Linux Enterprise Micro 5.3 | Fixed |
| SUSE Linux Enterprise Micro 5.4 | Fixed |
| SUSE Linux Enterprise Micro 5.5 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | Fixed |
| SUSE Linux Enterprise Server 15 SP7 | Fixed |
| SUSE Linux Enterprise Server 16.0 | Fixed |
| SUSE Linux Enterprise Server 16.1 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP7 | Fixed |
| SUSE Linux Enterprise Server for SAP applications 16.0 | Fixed |
| SUSE Linux Enterprise Server for SAP applications 16.1 | Fixed |
| SUSE Linux Micro 6.0 | Fixed |
| SUSE Linux Micro 6.1 | Fixed |
| SUSE Linux Micro 6.2 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP4 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP5 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP6 | Fixed |
| SUSE Linux Enterprise Server 12 SP5 | Fixed |
| SUSE Linux Enterprise Server 12 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Server 12 SP5-LTSS Extended Security | Fixed |
| SUSE Linux Enterprise Server 15 SP4 | Fixed |
| SUSE Linux Enterprise Server 15 SP4-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP5 | Fixed |
| SUSE Linux Enterprise Server 15 SP5-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP6 | Fixed |
| SUSE Linux Enterprise Server 15 SP6-LTSS | Fixed |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | Fixed |
| SUSE Manager Proxy 4.3 | Fixed |
| SUSE Manager Proxy LTS 4.3 | Fixed |
| SUSE Manager Retail Branch Server 4.3 | Fixed |
| SUSE Manager Retail Branch Server LTS 4.3 | Fixed |
| SUSE Manager Server 4.3 | Fixed |
| SUSE Manager Server LTS 4.3 | Fixed |
| SUSE CaaS Platform 3.0 | Fixed |
| SUSE CaaS Platform 4.0 | Fixed |
| SUSE Enterprise Storage 6 | Fixed |
| SUSE Enterprise Storage 7 | Fixed |
| SUSE Enterprise Storage 7.1 | Fixed |
| SUSE Linux Enterprise Desktop 12 | Fixed |
| SUSE Linux Enterprise Desktop 12 SP1 | Fixed |
| SUSE Linux Enterprise Desktop 12 SP2 | Fixed |
| SUSE Linux Enterprise Desktop 12 SP3 | Fixed |
| SUSE Linux Enterprise Desktop 12 SP4 | Fixed |
| SUSE Linux Enterprise Desktop 15 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP1 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP2 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP3 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP4 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP5 | Fixed |
| SUSE Linux Enterprise Desktop 15 SP6 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP1 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP2 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP3 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15 SP6 | Fixed |
| SUSE Linux Enterprise High Performance Computing 15-ESPOS | Fixed |
| SUSE Linux Enterprise High Performance Computing 15-LTSS | Fixed |
| SUSE Linux Enterprise Micro 5.0 | Fixed |
| SUSE Linux Enterprise Micro 5.1 | Fixed |
| SUSE Linux Enterprise Micro 5.2 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP1 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP2 | Fixed |
| SUSE Linux Enterprise Module for Basesystem 15 SP3 | Fixed |
| SUSE Linux Enterprise Point of Sale 12 SP2-CLIENT | Fixed |
| SUSE Linux Enterprise Real Time 15 SP2 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP3 | Fixed |
| SUSE Linux Enterprise Real Time 15 SP4 | Fixed |
| SUSE Linux Enterprise Server 12 | Fixed |
| SUSE Linux Enterprise Server 12 SP1 | Fixed |
| SUSE Linux Enterprise Server 12 SP1-LTSS | Fixed |
| SUSE Linux Enterprise Server 12 SP2 | Fixed |
| SUSE Linux Enterprise Server 12 SP2-BCL | Fixed |
| SUSE Linux Enterprise Server 12 SP2-ESPOS | Fixed |
| SUSE Linux Enterprise Server 12 SP2-LTSS | Fixed |
| SUSE Linux Enterprise Server 12 SP3 | Fixed |
| SUSE Linux Enterprise Server 12 SP3-BCL | Fixed |
| SUSE Linux Enterprise Server 12 SP3-ESPOS | Fixed |
| SUSE Linux Enterprise Server 12 SP3-LTSS | Fixed |
| SUSE Linux Enterprise Server 12 SP4 | Fixed |
| SUSE Linux Enterprise Server 12 SP4-ESPOS | Fixed |
| SUSE Linux Enterprise Server 12 SP4-LTSS | Fixed |
| SUSE Linux Enterprise Server 12-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 | Fixed |
| SUSE Linux Enterprise Server 15 SP1 | Fixed |
| SUSE Linux Enterprise Server 15 SP1-BCL | Fixed |
| SUSE Linux Enterprise Server 15 SP1-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP2 | Fixed |
| SUSE Linux Enterprise Server 15 SP2-BCL | Fixed |
| SUSE Linux Enterprise Server 15 SP2-LTSS | Fixed |
| SUSE Linux Enterprise Server 15 SP3 | Fixed |
| SUSE Linux Enterprise Server 15 SP3-BCL | Fixed |
| SUSE Linux Enterprise Server 15 SP3-LTSS | Fixed |
| SUSE Linux Enterprise Server 15-LTSS | Fixed |
| SUSE Linux Enterprise Server for Raspberry Pi 12 SP2 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 12 SP1 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 12 SP2 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 12 SP3 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 12 SP4 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP1 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP2 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP3 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | Fixed |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | Fixed |
| SUSE Manager Proxy 4.0 | Fixed |
| SUSE Manager Proxy 4.1 | Fixed |
| SUSE Manager Proxy 4.2 | Fixed |
| SUSE Manager Retail Branch Server 4.0 | Fixed |
| SUSE Manager Retail Branch Server 4.1 | Fixed |
| SUSE Manager Retail Branch Server 4.2 | Fixed |
| SUSE Manager Server 4.0 | Fixed |
| SUSE Manager Server 4.1 | Fixed |
| SUSE Manager Server 4.2 | Fixed |
| SUSE OpenStack Cloud 7 | Fixed |
| SUSE OpenStack Cloud 8 | Fixed |
| SUSE OpenStack Cloud 9 | Fixed |
| SUSE OpenStack Cloud Crowbar 8 | Fixed |
| SUSE OpenStack Cloud Crowbar 9 | Fixed |
| openSUSE Leap 15.3 | Fixed |
| openSUSE Leap 15.4 | Fixed |
| openSUSE Leap 15.5 | Fixed |
| openSUSE Leap 15.6 | Fixed |
| openSUSE Leap Micro 5.2 | Fixed |
| openSUSE Leap Micro 5.3 | Fixed |
| openSUSE Leap Micro 5.4 | Fixed |
| openSUSE Leap Micro 5.5 | Fixed |
| bci/kiwi kiwi-templates-Minimal kiwi-templates-Minimal-Cloud-sap kiwi-templates-Minimal-MS-HyperV-sap kiwi-templates-Minimal-VMware-sap kiwi-templates-Minimal-kvm-and-xen-sap rancher/elemental-builder-image/5.3 rancher/elemental-teal-rt/5.3 rancher/elemental-teal-rt/5.4 rancher/elemental-teal/5.3 rancher/elemental-teal/5.4 suse/hpc/warewulf4-x86_64/sle-hpc-node suse/manager/5.0/x86_64/server suse/multi-linux-manager/5.1/x86_64/server suse/multi-linux-manager/5.2/x86_64/server suse/sle-micro-rancher/5.2 suse/sle-micro-rancher/5.3 suse/sle-micro-rancher/5.4 suse/sle-micro/5.5 suse/sle-micro/base-5.5 suse/sle-micro/kvm-5.5 suse/sle-micro/rt-5.5 | Fixed |
Share
External POC / Exploit Code
Leaving vuln.today
EUVD-2026-31009