CVE-2021-20315
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedA 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceA locking protection bypass vulnerability in gnome-shell allows a physically present attacker to kill running applications and launch new ones as the locked user when the 'Application menu' or 'Window list' GNOME extensions are enabled, bypassing the session lock screen.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 3.32.2= 8CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Physical
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed gnome-shell versionRun `gnome-shell --version` or look up the package version using your package manager (e.g., `rpm -q gnome-shell`)Affected if Version is below 3.32.2, or on CentOS Stream 8 with gnome-shell installed
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Identify the OS distribution and versionCheck if the system is CentOS Stream 8 using `cat /etc/os-release` or `cat /etc/centos-release`Affected if System is CentOS Stream 8 with gnome-shell installed
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Determine if Application Menu extension is enabledOpen GNOME Extensions app, or check via command line using `gsettings get org.gnome.shell enabled-extensions` to see if '[email protected]' or similar app-menu extension appears in the listAffected if The Application Menu extension appears in the enabled extensions list
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Determine if Window List extension is enabledOpen GNOME Extensions app, or check via command line using `gsettings get org.gnome.shell enabled-extensions` to see if '[email protected]' or similar window-list extension appears in the listAffected if The Window List extension appears in the enabled extensions list
You are affected if gnome-shell version is below 3.32.2 (or you are on CentOS Stream 8) AND either the Application menu or Window list extension is enabled on your system.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped3.32.2
Disable the 'Application menu' and 'Window list' GNOME extensions until gnome-shell is patched, and apply available security updates for CentOS Stream 8.
GNOME Shell 3.32.2 or later (via CentOS Stream 8 package update)
- Update system packages: dnf update gnome-shell (or yum update gnome-shell)
- After the update completes, verify the installed version: rpm -q gnome-shell
- Restart the GNOME session or reboot the system to apply the update
- Confirm the system is running GNOME Shell version 3.32.2 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing1.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,744.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-20315 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-20315 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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