CVE-2025-3931
Description
A flaw was found in Yggdrasil, which acts as a system broker, allowing the processes to communicate to other children's "worker" processes through the DBus component. Yggdrasil creates a DBus method to dispatch messages to workers. However, it misses authentication and authorization checks, allowing every system user to call it. One available Yggdrasil worker acts as a package manager with capabilities to create and enable new repositories and install or remove packages.
This flaw allows an attacker with access to the system to leverage the lack of authentication on the dispatch message to force the Yggdrasil worker to install arbitrary RPM packages. This issue results in local privilege escalation, enabling the attacker to access and modify sensitive system data.
Statement
This vulnerability qualifies as Important rather than Moderate due to its direct violation of privilege boundaries and its broad post-install attack surface. The core issue lies in the com.redhat.Yggdrasil1.Dispatch() method being exposed over the system DBus without any authentication or authorization, enabling any local unprivileged user to interface with a privileged backend (package-manager worker). By leveraging this unprotected method, an attacker can install arbitrary software, execute payloads, and gain full root access, thus achieving a complete Local Privilege Escalation (LPE). While exploitation requires local access, the flaw exists in a default service path (rhc connect) recommended during system registration, increasing its exposure. Furthermore, the ability to manipulate package installation flows — a highly privileged operation — indicates a severe trust boundary violation.
Mitigation
Mitigation is either unavailable or does not meet Red Hat Product Security standards for usability, deployment, applicability, or stability.
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 | 7.8 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| 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 | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Other
Technical Impact: Other; Alter Execution Logic
Acknowledgements
This issue was discovered by Thibault Guittet (Red Hat).
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