CVE-2021-20315
Description
A locking protection bypass flaw was found in some versions of gnome-shell as shipped within CentOS Stream 8, when the "Application menu" or "Window list" GNOME extensions are enabled. This flaw allows a physical attacker who has access to a locked system to kill existing applications and start new ones as the locked user, even if the session is still locked.
Statement
The flaw only affects some specific versions of CentOS Stream 8. This issue did not affect the versions of gnome-shell as shipped with Red Hat Enterprise Linux 7, and 8 as they did not include the vulnerable code.
Mitigation
Disable enabled GNOME extensions, such as "Application menu" or "Window list".
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.7 | 6.1 | N/A |
| Attack Vector | Physical | Physical | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | Low | None | N/A |
| Integrity Impact | High | High | N/A |
| Availability Impact | Low | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L
NVD: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU)
Inconsistent locking discipline can lead to deadlock.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
