dbcve.org
LinuxOperating system · Redhat

CVE-1999-0192

HIGH · 10.0 CVSS v2.0 Published 1997-10-18
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
Buffer overflow in telnet daemon tgetent routing allows remote attackers to gain root access via the TERMCAP environmental variable.

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 confidence

Buffer overflow in the telnet daemon's tgetent function allows remote attackers to execute arbitrary code by overflowing a buffer through the TERMCAP environment variable, potentially granting root privileges.

MitigationDisable the telnet service immediately and migrate to SSH for remote access. If telnet is required, apply vendor patches or consider upgrading to systems with patched telnet daemons.

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
LinuxOperating system
Affected:= 4.0= 4.1= 4.2= 5.0= 5.1= 5.2= 6.0
Slackware LinuxOperating system
Affected:= 3.2= 3.3= 3.4= 3.5= 3.6= 3.9= 4.0

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. Verify if telnet daemon is installed
    Check for the presence of the telnet daemon package or binary (typically in.telnetd or telnetd) on the system
    Affected if The telnet daemon package is installed on a Red Hat Linux 4.0-6.0 or Slackware Linux 3.2-4.0 system
  2. Check if telnet service is running
    Verify whether the telnet daemon is actively listening on port 23 or has been enabled in inetd/xinetd configuration
    Affected if The telnet service is enabled and running, exposing the vulnerability to network attackers
  3. Identify the telnet package version
    Query the installed telnet daemon package version using the system's package manager (rpm for Red Hat, pkgtools for Slackware)
    Affected if The installed version matches one of the affected Red Hat versions (4.0, 4.1, 4.2, 5.0, 5.1, 5.2, 6.0) or Slackware versions (3.2, 3.3, 3.4, 3.5, 3.6, 3.9, 4.0)
  4. Confirm TERMCAP environment variable handling
    Review telnet daemon source code or behavior to verify it processes the TERMCAP environment variable without proper bounds checking in the tgetent function
    Affected if The telnet daemon processes TERMCAP environment variables from remote clients, allowing buffer overflow exploitation

A system is affected if it runs an unpatched telnet daemon from Red Hat Linux 4.0-6.0 or Slackware Linux 3.2-4.0 that processes the TERMCAP environment variable, allowing remote attackers to potentially execute arbitrary code with root privileges.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Disable the telnet service immediately and migrate to SSH for remote access. If telnet is required, apply vendor patches or consider upgrading to systems with patched telnet daemons.

Recommended fix High confidence
  1. Disable the telnet daemon (telnetd) service to prevent exploitation
  2. Remove or uninstall the telnet server package if not required
  3. If telnet access is required, replace with SSH (OpenSSH) which is not affected by this vulnerability
  4. Ensure TERMCAP environment variable is not passed to any privileged processes
  5. Apply any distribution-provided security patches for telnetd if available (though unlikely for these EOL versions)
Caveat Disabling telnet will break any systems or workflows relying on telnet for remote access; migrate to SSH

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing6.0 h
  • Review / QA3.0 h
27.0 hours of engineering $4,800
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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-1999-0192 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