CVE-2018-14665
Description
An incorrect permission check for -modulepath and -logfile options when starting Xorg X server allows unprivileged users with the ability to log in to the system via physical console to escalate their privileges and run arbitrary code under root privileges.
Statement
This issue did not affect the versions of xorg-x11-server as shipped with Red Hat Enterprise Linux 5 and 6, as well as Red Hat Enterprise Linux 7 prior to 7.4, as they did not allow the use of vulnerable command line options when running with elevated privileges.
The default X server configuration in Red Hat Enterprise Linux only allows users logged in on the system's physical console to run Xorg X server. Therefore, users which only have remote access to the the system (for example using SSH) can not exploit this flaw.
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 | 6.6 | 6.6 | N/A |
| Attack Vector | Physical | Physical | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | High | High | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.0/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Access Control
Technical Impact: Gain Privileges or Assume Identity
If privileges are not dropped, neither are access rights of the user. Often these rights can be prevented from being dropped.
Access Control,Non-Repudiation
Technical Impact: Gain Privileges or Assume Identity; Hide Activities
If privileges are not dropped, in some cases the system may record actions as the user which is being impersonated rather than the impersonator.
Acknowledgements
Red Hat would like to thank Narendra Shinde for reporting this issue.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
