Ubuntu LinuxOperating system · Canonical
CVE-2018-1000097
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 · uneditedSharutils sharutils (unshar command) version 4.15.2 contains a Buffer Overflow vulnerability in Affected component on the file unshar.c at line 75, function looks_like_c_code. Failure to perform checking of the buffer containing input line. that can result in Could lead to code execution. This attack appear to be exploitable via Victim have to run unshar command on a specially crafted file..
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 confidenceBuffer overflow vulnerability in Sharutils 4.15.2's unshar command. The looks_like_c_code function in unshar.c at line 75 fails to perform bounds checking on the buffer containing the input line before processing it. Successful exploitation allows code execution if a victim runs unshar on a specially crafted file.
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
Ubuntu LinuxOperating system
= 14.04= 16.04= 17.10
Debian LinuxOperating system
= 8.0= 9.0= 4.15.2CVSS 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
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:L/AC:L/PR:N/UI:R/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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Verify sharutils package is installedRun: dpkg -l | grep sharutils (Debian/Ubuntu) or rpm -qa | grep sharutils (RPM-based)Affected if Package is not installed means not affected in this way
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Check installed unshar versionRun: unshar --version or dpkg -l sharutilsAffected if Version shows 4.15.2 or falls within the affected distribution versions (Ubuntu 14.04, 16.04, 17.10; Debian 8.0, 9.0) with unpatched sharutils
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Locate the unshar binaryRun: which unsharAffected if Binary exists at a standard path, the vulnerability is present if version check above is positive
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Inspect the vulnerable function sourceCheck if unshar.c source file contains unpatched looks_like_c_code function around line 75 without bounds checkingAffected if Source code shows missing buffer length validation before processing input lines
You are affected if unshar from sharutils version 4.15.2 or an unpatched version from the listed Ubuntu/Debian releases is installed and accessible on your 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.
From vendor dataAvoid running the unshar command on untrusted or specially crafted files. Apply a source code fix to add proper buffer length checking in the looks_like_c_code function, or upgrade to a patched version when available.
Fix this in Ubuntu Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 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 $2,272.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-1000097 — 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-2018-1000097 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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- Version or environment caveats, and links to real fixes
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