FedoraOperating system · Fedoraproject
CVE-2021-42382
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 use-after-free in Busybox's awk applet leads to denial of service and possibly code execution when processing a crafted awk pattern in the getvar_s function
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 confidenceA use-after-free vulnerability in BusyBox's awk applet in the getvar_s function allows attackers to cause denial of service or potentially execute arbitrary code by processing a specially crafted awk pattern.
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
FedoraOperating system
= 33= 34>= 1.26.0, <= 1.33.1CVSS 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
- Network
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/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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Determine BusyBox versionRun `busybox --version` or `busybox -v` to see the installed BusyBox version numberAffected if The version falls within >= 1.26.0 and <= 1.33.1
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Confirm awk applet is availableRun `busybox awk` or check if the awk binary/symlink exists in the system (e.g., `which awk` or `ls -l /bin/awk`)Affected if The awk applet is present and executable on the system
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Check if awk is the BusyBox implementationRun `busybox awk --help` or `file $(which awk)` to verify it is the BusyBox awk applet rather than a standalone gawk/mawkAffected if The awk implementation is provided by BusyBox (not gawk or mawk)
The system is affected if BusyBox version is between 1.26.0 and 1.33.1 inclusive AND the awk applet is enabled/available on the 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 · scopedUpdate BusyBox to the latest patched version. If immediate updates are not feasible, consider disabling or restricting access to the awk applet in affected deployments.
Busybox >= 1.34.0
- Identify the specific Busybox package installed on the system (e.g., via 'rpm -q busybox' or 'dpkg -l busybox')
- For Fedora systems: Run 'sudo dnf update busybox' to upgrade to the fixed package version
- Verify the upgrade was successful by checking the Busybox version (e.g., 'busybox --version') and confirm it is version 1.34.0 or later
- For embedded systems using Busybox: Recompile Busybox from source using version 1.34.0 or later from the official Busybox website
- Test the awk applet functionality after upgrade to ensure the patch does not break legitimate awk scripts
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Fedora
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-42382 — 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-2021-42382 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
- No weaponised exploit code, or anything meant to cause harm
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