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KerberosApplication · Mit

CVE-2009-0844

MEDIUM · 5.8 CVSS v2.0 Published 2009-04-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
67/100
Remediation priority · Elevated
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
The get_input_token function in the SPNEGO implementation in MIT Kerberos 5 (aka krb5) 1.5 through 1.6.3 allows remote attackers to cause a denial of service (daemon crash) and possibly obtain sensitive information via a crafted length value that triggers a buffer over-read.

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

The get_input_token function in the SPNEGO implementation of MIT Kerberos 5 versions 1.5 through 1.6.3 contains a buffer over-read vulnerability. A remote attacker can send a crafted length value that causes the function to read beyond buffer boundaries, leading to daemon crash (denial of service) and potential information disclosure.

MitigationUpgrade MIT Kerberos 5 to version 1.6.4 or later, which contains the patch for this vulnerability. If immediate patching is not possible, consider disabling SPNEGO or restricting network access to Kerberos services as a temporary measure.

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
KerberosApplication
Affected:= 5-1.6.3
Kerberos 5Application
Affected:all versions= 1.5= 1.5.1= 1.5.2= 1.5.3= 1.6= 1.6.1= 1.6.2

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
M
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
Partial

AV:N/AC:M/Au:N/C:P/I:N/A:P

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. Identify MIT Kerberos 5 installation and version
    Run 'krb5-config --version' or check package manager (dpkg -l krb5, rpm -q krb5)
    Affected if Version is 1.5.x, 1.6.x, 1.6.1, 1.6.2, or 1.6.3 (falls within 1.5 through 1.6.3 range)
  2. Confirm the SPNEGO GSS-API mechanism is in use
    Inspect Kerberos configuration files (/etc/krb5.conf) for 'GSSAPIMech' or 'mechs' settings, or check application logs for SPNEGO/GSSAPI usage
    Affected if SPNEGO (security mechanism) is enabled or applications use GSS-API authentication with SPNEGO
  3. Verify the krb5-libs or krb5-server packages
    Query installed packages: 'rpm -qa | grep -i krb5' (RHEL/CentOS) or 'dpkg -l | grep -i krb5' (Debian)
    Affected if Package version matches the vulnerable 1.5-1.6.3 range

System is affected if MIT Kerberos 5 version 1.5 through 1.6.3 is installed and SPNEGO/GSS-API authentication is in use

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 MIT Kerberos 5 to version 1.6.4 or later, which contains the patch for this vulnerability. If immediate patching is not possible, consider disabling SPNEGO or restricting network access to Kerberos services as a temporary measure.

Fix this in Kerberos Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA3.0 h
21.0 hours of engineering $3,680
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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-2009-0844 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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