LinuxOperating system · Redhat
CVE-2000-0391
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 · uneditedBuffer overflow in krshd in Kerberos 5 allows remote attackers to gain root privileges.
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 confidenceBuffer overflow vulnerability in krshd, the Kerberos 5 remote shell daemon, allows remote attackers to execute arbitrary code with root privileges by overflowing a buffer in the daemon's handling of incoming connections.
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
= 6.2= 4.0= 5.0= 4.0= 1.0= 1.1.1CVSS 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 checksWork through these to decide whether this CVE applies to you.
-
Identify if MIT Kerberos 5 is installedRun 'klist -V' or check for the presence of /usr/krb5 directory, or use package manager: 'rpm -qa | grep -i krb5' (Red Hat) or 'dpkg -l | grep -i krb5' (Debian)Affected if MIT Kerberos 5 versions 1.0 or 1.1.1 are installed, or the package name matches the affected Red Hat/Cygnus products listed
-
Determine the exact Kerberos 5 versionRun 'kinit --version' or check the krb5-libs package version with 'rpm -q krb5-libs'Affected if Version is exactly 1.0 or 1.1.1 for MIT Kerberos 5
-
Check if the krshd daemon is presentLook for /usr/sbin/krshd or run 'which krshd', and check for the krb5-server package with 'rpm -qa | grep krb5-server'Affected if The krshd binary exists in the system
-
Verify if krshd service is enabled or runningCheck for running process: 'ps aux | grep krshd', and check init scripts: 'ls /etc/rc.d/rc3.d/ | grep -i krb' or check systemctl status for krb5-telnet or similar servicesAffected if The krshd daemon is running or enabled to start at boot, exposing the vulnerability to network
-
Check if port 514 is exposed to networkRun 'netstat -tlnp | grep 514' or 'ss -tlnp | grep 514' to see if the service is listening on network interfaces, and verify firewall rules with 'iptables -L -n'Affected if Port 514 (shell/kshell) is listening on a non-localhost interface, making the flaw remotely exploitable
The system is affected if MIT Kerberos 5 version 1.0 or 1.1.1 (or Red Hat Linux 6.2, Cygnus products) is installed AND the krshd daemon is running and accessible on the network.
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 dataApply available patches for Kerberos 5 to address the buffer overflow, or if krshd is not required, disable the service. Network segmentation and restricting access to port 514 (shell) can provide additional defense-in-depth.
Fix this in Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 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 $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2000-0391 — 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-2000-0391 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
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.
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.
- 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