dbcve.org
FreeBSDOperating system

CVE-2001-0093

HIGH · 7.2 CVSS v2.0 Published 2001-02-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
Vulnerability in telnetd in FreeBSD 1.5 allows local users to gain root privileges by modifying critical environmental variables that affect the behavior of telnetd.

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

Local privilege escalation vulnerability in FreeBSD 1.5's telnetd daemon allows authenticated local users to gain root privileges by manipulating environmental variables that influence telnetd's behavior. The vulnerability stems from insufficient validation of environment variables passed to or set by the telnetd process.

MitigationUpgrade from FreeBSD 1.5 (end-of-life) to a supported release; if telnetd must remain operational, disable it and migrate to SSH; apply any available vendor patches for this issue.

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:= 1.5

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. Verify FreeBSD version
    Run 'uname -r' to determine the installed FreeBSD version
    Affected if Version reported is FreeBSD 1.5
  2. Confirm telnetd is enabled
    Check if the telnetd service is running or configured to start. Examine process list with 'ps aux | grep telnetd' and check /etc/inetd.conf for telnet entries
    Affected if telnetd daemon is running or configured to start on system boot
  3. Identify telnetd binary
    Locate the telnetd binary on the system, typically found at /usr/libexec/telnetd or /usr/sbin/telnetd
    Affected if telnetd binary exists and is the one shipped with FreeBSD 1.5

System is affected only if running FreeBSD 1.5 with telnetd daemon enabled and operational

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 from FreeBSD 1.5 (end-of-life) to a supported release; if telnetd must remain operational, disable it and migrate to SSH; apply any available vendor patches for this issue.

Fix this in FreeBSD Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing3.0 h
  • Review / QA2.0 h
17.0 hours of engineering $3,050
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,880.

Scan for this in your stack

Free · runs locally
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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-2001-0093 in production — separate from our analysis above.

No notes yet

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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
  • 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