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Kexec ToolsApplication · Kexec Tools Project

CVE-2021-20269

MEDIUM · 5.5 CVSS v3.1 Published 2022-03-10
Fix available
A fix is available. Upgrade to 2.0.20-47 / 2.0.21-8 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click

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 · unedited
A flaw was found in the permissions of a log file created by kexec-tools. This flaw allows a local unprivileged user to read this file and leak kernel internal information from a previous panic. The highest threat from this vulnerability is to confidentiality. This flaw affects kexec-tools shipped by Fedora versions prior to 2.0.21-8 and RHEL versions prior to 2.0.20-47.

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 · high confidence

The kexec-tools package creates a log file with overly permissive permissions that allows any local unprivileged user to read it. This log file can contain kernel internal information from a previous kernel panic, enabling information disclosure.

MitigationUpgrade kexec-tools to version 2.0.21-8 or later on Fedora, or 2.0.20-47 or later on RHEL. Alternatively, identify and secure permissions on the affected log file (typically in /var/log/) to restrict read access.

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
Kexec ToolsApplication
Affected:< 2.0.21-8< 2.0.20-47

CVSS 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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

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 checks

Work through these to decide whether this CVE applies to you.

  1. Check if kexec-tools is installed
    Run 'rpm -q kexec-tools' or 'dpkg -l kexec-tools' to see if the package is installed
    Affected if The package is not installed
  2. Determine installed kexec-tools version
    Run 'rpm -q --queryformat '%{VERSION}-%{RELEASE}' kexec-tools' or 'dpkg -s kexec-tools' to get the exact version number
    Affected if Version is earlier than 2.0.21-8 or earlier than 2.0.20-47 depending on distribution
  3. Locate kexec-related log files
    Search for log files in /var/log/ that may have been created by kexec-tools, such as 'kexec.log', 'kdump.log', or files containing 'kexec' in the name. Use: 'find /var/log -iname '*kexec*' -o -iname '*kdump*' 2>/dev/null'
    Affected if No kexec-related log files exist in /var/log/ (not vulnerable because the problematic file has not been created)
  4. Inspect log file permissions
    Run 'ls -la' on the identified kexec log files to check their permissions. Look for 'rw-r--r--' (644) or similar world-readable settings
    Affected if The log file is readable by 'other' users (permissions include 'r--' for others, such as 644 or 666)

A user is affected if kexec-tools version is less than 2.0.21-8 (or 2.0.20-47 on RHEL) AND a kexec-related log file exists with world-readable permissions, allowing any local user to read potentially sensitive kernel panic information.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 2.0.20-47 / 2.0.21-8 or later
Fixed in 2.0.20-472.0.21-8
Interim mitigation

Upgrade kexec-tools to version 2.0.21-8 or later on Fedora, or 2.0.20-47 or later on RHEL. Alternatively, identify and secure permissions on the affected log file (typically in /var/log/) to restrict read access.

Recommended fix High confidence

kexec-tools version 2.0.21-8 (Fedora) or 2.0.20-47 (RHEL)

  1. Update the package repository metadata: sudo dnf check-update or sudo yum check-update
  2. Upgrade kexec-tools to the fixed version: sudo dnf upgrade kexec-tools or sudo yum update kexec-tools
  3. Verify the installed version is 2.0.21-8 or later for Fedora, or 2.0.20-47 or later for RHEL: rpm -q kexec-tools
  4. Restart any services that depend on kexec functionality if necessary

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Kexec Tools Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-20269 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data