CVE-2021-20269

Kernel information disclosure via world-readable crash logs

Published Mar 9, 2022 · Updated Aug 3, 2024

Information disclosure in kexec-tools on affected Fedora and RHEL releases allows local users to read prior kernel panic data. Shell redirection creates kexec-dmesg.log and vmcore-dmesg.txt under the default umask, leaving group and other users with read access. Exploitation requires a local account and a crash-generated log containing kernel ring-buffer or panic-backtrace information.

CVSS severity5.5
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in kexec-tools on affected Fedora and RHEL releases allows local users to read prior kernel panic data. Shell redirection creates kexec-dmesg.log and vmcore-dmesg.txt under the default umask, leaving group and other users with read access. Exploitation requires a local account and a crash-generated log containing kernel ring-buffer or panic-backtrace information.

The record

CVE
CVE-2021-20269
Published
Mar 9, 2022
Updated
Aug 3, 2024
Vendor
Kexec-tools Project
Product
kexec-tools
Classifications
CWE-276, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 9, 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=Fedora kexec-tools versions prior to 2.0.21-8 and RHEL kexec-tools versions prior to 2.0.20-47

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Kexec-tools Project · kexec-toolsversion=Fedora kexec-tools versions prior to 2.0.21-8 and RHEL kexec-tools versions prior to 2.0.20-47

Published CVSS scores

5.5NISTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
2.1NISTAV:L/AC:L/Au:N/C:P/I:N/A:N
4.7Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-276Incorrect Default Permissions
T1005Data from Local System

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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