Debian LinuxOperating system · Debian
CVE-2018-1071
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 · uneditedzsh through version 5.4.2 is vulnerable to a stack-based buffer overflow in the exec.c:hashcmd() function. A local attacker could exploit this to cause a denial of service.
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 confidencezsh through version 5.4.2 contains a stack-based buffer overflow vulnerability in the exec.c:hashcmd() function. A local attacker who can execute commands on the affected system could trigger this overflow by manipulating input to the hashcmd function, potentially causing the shell to crash or behave unpredictably.
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
Debian LinuxOperating system
= 7.0
Ubuntu LinuxOperating system
= 14.04= 16.04= 17.10
Enterprise Linux DesktopOperating system
= 7.0
Enterprise Linux ServerOperating system
= 7.0
Enterprise Linux WorkstationOperating system
= 7.0<= 5.4.2CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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 if zsh is installedRun 'which zsh' or 'command -v zsh' to locate the zsh binaryAffected if zsh is not found on the system, the vulnerability does not apply
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Determine the installed zsh versionRun 'zsh --version' to retrieve the version numberAffected if The version cannot be determined or zsh is not responding to the version flag
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Compare version against affected rangeCompare the output from 'zsh --version' to the affected range: any version of zsh <= 5.4.2 is vulnerableAffected if The installed version is 5.4.2 or any earlier version (e.g., 5.4.1, 5.3.1, etc.)
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Identify the Linux distribution package version (if applicable)For Debian-based systems: 'dpkg -l | grep zsh'; For RHEL-based systems: 'rpm -qa | grep zsh'Affected if The package version (if displayed) is <= 5.4.2-0 or corresponds to an unpatched release
If zsh is installed and the version is 5.4.2 or lower, the system is affected by this stack-based buffer overflow vulnerability in the hashcmd function.
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.
From vendor dataUpdate zsh to a version newer than 5.4.2. Most Linux distributions and package managers have released patches for this vulnerability. Verify the installed version using 'zsh --version' and apply available security updates.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation1.0 h
- Implementation1.0 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 $1,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-1071 — 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-2018-1071 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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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.
- 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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