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FreeBSDOperating system

CVE-2006-4172

HIGH · 7.2 CVSS v2.0 Published 2006-09-26
Fix available
A fix is available. Upgrade to after 5.5 or later.
See remediation →
77/100
Remediation priority · High
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
Integer overflow vulnerability in the i386_set_ldt call in FreeBSD 5.5, and possibly earlier versions down to 5.2, allows local users to cause a denial of service (crash) and possibly execute arbitrary code via unspecified vectors, a different vulnerability than CVE-2006-4178.

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

Integer overflow in the i386_set_ldt system call in FreeBSD 5.2-5.5 allows local authenticated users to potentially execute arbitrary code with kernel privileges via unspecified vectors, leading to privilege escalation and possible system crash.

MitigationApply the vendor-supplied FreeBSD security patch for this vulnerability. Restrict local shell access to untrusted users as an interim measure until patching is complete.

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
FreeBSDOperating system
Affected:<= 5.5= 5.2= 5.2.1= 5.3= 5.4

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
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:L/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. Check FreeBSD release version
    Run 'uname -r' or examine /etc/fstab and boot logs to identify the installed FreeBSD version
    Affected if The version begins with 5.2, 5.3, 5.4, or 5.5 (or any 5.x release below 5.5)
  2. Verify system architecture
    Run 'uname -m' or check if the system is running a 32-bit i386 kernel
    Affected if The system is running on i386 architecture and uses the i386_set_ldt system call
  3. Confirm kernel source level
    Check the kernel source version in /usr/src/sys/conf/NOTES or compare kernel version from 'uname -v' against affected release tags
    Affected if The kernel was built from sources matching affected FreeBSD 5.2-5.5 releases
  4. Check for local user accounts
    Review /etc/passwd and verify if non-privileged local accounts exist using 'getent passwd'
    Affected if Local authenticated users have shell access to the system

The system is affected if it runs FreeBSD 5.2 through 5.5 on i386 architecture and allows local authenticated users access to the i386_set_ldt system call.

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
Upgrade available Upgrade to a release after 5.5
Interim mitigation

Apply the vendor-supplied FreeBSD security patch for this vulnerability. Restrict local shell access to untrusted users as an interim measure until patching is complete.

Fix this in FreeBSD Scoped from the published advisory
  • Consultation8.0 h
  • Implementation16.0 h
  • Testing12.0 h
  • Review / QA8.0 h
44.0 hours of engineering $7,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $12,352.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2006-4172 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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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-2006-4172 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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