CVE-2026-70463
Description
An authorization bypass flaw was found in the rsync daemon. The auth users directive parser incorrectly handles group names containing spaces due to comma-only tokenization. This flaw causes deny rules to be silently discarded, allowing an authenticated user to bypass restrictions and gain unauthorized access to restricted modules.
Statement
This is an Important authorization bypass in rsync, affecting configurations that utilize the auth users directive with group names containing spaces. The flaw allows an authenticated, but unauthorized, user to access restricted rsync modules due to incorrect parsing of deny rules. This bypass occurs because the rsync parser fails to properly tokenize group names with embedded spaces, silently discarding intended access restrictions.
Mitigation
To prevent this authorization bypass, ensure that no group names containing spaces are used within the `auth users` directive in the `rsyncd.conf` configuration file. Review and update any existing configurations to remove spaces from group names in this directive. After making changes, restart the `rsync` service for the new configuration to take effect. For example, use `systemctl restart rsyncd` if managing the service with systemd. Note that restarting the service will temporarily interrupt active rsync operations.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 8.1 | N/A | 8.1 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
An attacker could bypass intended access restrictions to read sensitive data, either by reading the data directly from a data store that is not correctly restricted, or by accessing insufficiently-protected, privileged functionality to read the data.
Integrity
Technical Impact: Modify Application Data; Modify Files or Directories
An attacker could bypass intended access restrictions to modify sensitive data, either by writing the data directly to a data store that is not correctly restricted, or by accessing insufficiently-protected, privileged functionality to write the data.
Access Control
Technical Impact: Gain Privileges or Assume Identity; Bypass Protection Mechanism
An attacker could bypass intended access restrictions to gain privileges by modifying or reading critical data directly, or by accessing privileged functionality.
Confidentiality,Integrity,Availability
Technical Impact: Execute Unauthorized Code or Commands
An attacker could use elevated privileges to execute unauthorized commands or code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
An attacker could gain unauthorized access to resources on the system and excessively consume those resources, leading to a denial of service.
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