CVE-2021-20315

Session control via lock-screen extension exposure

Published Feb 18, 2022 · Updated Aug 3, 2024

Lock-screen protection bypass in GNOME Shell 3.32.2-39.el8 allows physically proximate attackers to launch or terminate applications. With Application Menu or Window List extensions enabled on CentOS Stream 8, their controls remain visible and operable after the session locks. Physical access to an already locked session is required; actions run as the logged-in user and can alter that user's session without unlocking it.

CVSS severity6.1
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Lock-screen protection bypass in GNOME Shell 3.32.2-39.el8 allows physically proximate attackers to launch or terminate applications. With Application Menu or Window List extensions enabled on CentOS Stream 8, their controls remain visible and operable after the session locks. Physical access to an already locked session is required; actions run as the logged-in user and can alter that user's session without unlocking it.

The record

CVE
CVE-2021-20315
Published
Feb 18, 2022
Updated
Aug 3, 2024
Vendor
GNOME
Product
GNOME Shell
Classifications
CWE-667
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 18, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=gnome-shell 3.32.2-40.el8

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

GNOME · GNOME Shellversion=gnome-shell 3.32.2-40.el8

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
3.6NIST NVDAV:L/AC:L/Au:N/C:N/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-667Improper Locking

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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