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Subsystem For Unix Based ApplicationsApplication · Microsoft

CVE-2009-1216

HIGH · 10.0 CVSS v2.0 Published 2009-04-01
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges 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
Multiple unspecified vulnerabilities in (1) unlzh.c and (2) unpack.c in the gzip libraries in Microsoft Windows Server 2008, Windows Services for UNIX 3.0 and 3.5, and the Subsystem for UNIX-based Applications (SUA); as used in gunzip, gzip, pack, pcat, and unpack 7.x before 7.0.1701.48, 8.x before 8.0.1969.62, and 9.x before 9.0.3790.2076; allow remote attackers to execute arbitrary code via unknown vectors.

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 confidence

Multiple unspecified vulnerabilities in unlzh.c and unpack.c in the gzip libraries used by gunzip, gzip, pack, pcat, and unpack utilities on Windows Server 2008, Windows Services for UNIX 3.0/3.5, and SUA allow remote attackers to execute arbitrary code via unknown vectors. The vulnerabilities affect versions 7.x before 7.0.1701.48, 8.x before 8.0.1969.62, and 9.x before 9.0.3790.2076.

MitigationUpgrade the affected gzip utilities (gunzip, gzip, pack, pcat, unpack) to version 7.0.1701.48 or later for 7.x, 8.0.1969.62 or later for 8.x, or 9.0.3790.2076 or later for 9.x. If these legacy components cannot be updated, consider removing or disabling the UNIX-based Applications subsystem if not required.

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
Subsystem For Unix Based ApplicationsApplication
Affected:all versions
Windows Services For UnixApplication
Affected:= 3.0= 3.5
Windows Server 2008Operating system
Affected:all versions
Windows VistaOperating system
Affected:all versions

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
Network
Complexity
Low
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:L/Au:N/C:C/I:C/A:C

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. Confirm if Windows Subsystem for UNIX-Based Applications (SUA) or Windows Services for UNIX (SFU) is installed
    Check the Windows feature list or look for the presence of SUA/SFU directories in Program Files or the Windows system directory. On Windows Server 2008, open Server Manager and look under Features for 'Subsystem for UNIX-based Applications'. On Vista, check Programs and Features for Microsoft Windows Services for UNIX.
    Affected if The subsystem is installed and the vulnerable gzip utilities are present on the system
  2. Locate the gzip utilities on the system
    Search for gzip.exe, gunzip.exe, pack.exe, pcat.exe, and unpack.exe in common SUA/SFU installation paths such as C:\Program Files\Windows Services for UNIX\bin\ or C:\Windows\SUA\bin\.
    Affected if Any of these five utilities (gzip, gunzip, pack, pcat, unpack) are found on the system with the vulnerable versions
  3. Determine the version of the installed gzip utilities
    Run 'gzip --version' or right-click on each utility file and select Properties, then check the Details tab for version information. Note the exact version number displayed.
    Affected if The installed version is 7.x before 7.0.1701.48, 8.x before 8.0.1969.62, or 9.x before 9.0.3790.2076
  4. Identify the gzip library version in use
    Check the file properties of unlzh.c or unpack.c if accessible in the SUA/SFU installation directory, or attempt to run the utilities with verbose output to see library version information.
    Affected if The underlying gzip library version matches the vulnerable release ranges listed

The system is affected if Windows Subsystem for UNIX-Based Applications or Windows Services for UNIX is installed with gzip utilities (gzip, gunzip, pack, pcat, or unpack) at version 7.x before 7.0.1701.48, 8.x before 8.0.1969.62, or 9.x before 9.0.3790.2076.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade the affected gzip utilities (gunzip, gzip, pack, pcat, unpack) to version 7.0.1701.48 or later for 7.x, 8.0.1969.62 or later for 8.x, or 9.0.3790.2076 or later for 9.x. If these legacy components cannot be updated, consider removing or disabling the UNIX-based Applications subsystem if not required.

Fix this in Subsystem For Unix Based Applications Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
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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-2009-1216 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
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  • Version or environment caveats, and links to real fixes
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