Kerberos 5Application · Mit

CVE-2007-3149

HIGH · 7.2 CVSS v2.0 Published 2007-06-11
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
sudo, when linked with MIT Kerberos 5 (krb5), does not properly check whether a user can currently authenticate to Kerberos, which allows local users to gain privileges, in a manner unintended by the sudo security model, via certain KRB5_ environment variable settings. NOTE: another researcher disputes this vulnerability, stating that the attacker must be "a user, who can already log into your system, and can already use sudo."

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

When sudo is linked with MIT Kerberos 5, it fails to properly validate the user's current Kerberos authentication state when processing KRB5_ environment variables. This allows a local user who already has sudo access to manipulate these variables to bypass the intended sudo security checks and gain elevated privileges.

MitigationUpdate sudo to a version that properly validates Kerberos authentication state or configure sudo to strip KRB5_ environment variables via the env_reset option in /etc/sudoers. If Kerberos authentication via sudo is not required, rebuild sudo without MIT Kerberos 5 linkage.

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
Kerberos 5Application
Affected:all versions
SudoApplication
Affected:= 1.6.8_p12

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 installed sudo version
    Run 'sudo -V' or 'rpm -q sudo' / 'dpkg -l sudo' to get the sudo version number
    Affected if The version is exactly 1.6.8_p12
  2. Verify sudo is linked with MIT Kerberos 5
    Run 'ldd $(which sudo) | grep -i krb' or 'ldconfig -p | grep -i krb5' to check if sudo has a runtime dependency on Kerberos libraries
    Affected if Kerberos libraries (libkrb5) appear in the linked libraries output
  3. Confirm KRB5_ environment variables are not stripped
    Check /etc/sudoers for the env_reset option. Run 'sudo -V' and look for 'env_reset' in the environment section. Also check if 'env_keep' includes KRB5_ variables with 'sudo grep -i krb5 /etc/sudoers'
    Affected if env_reset is not present, or KRB5_ variables are explicitly allowed via env_keep, or no such controls exist
  4. Verify user has existing sudo privileges
    Run 'sudo -l' as the target user to list their sudo permissions
    Affected if The user already has sudo access configured in /etc/sudoers (the attack requires an existing sudo user to manipulate KRB5_ vars)

You are affected if sudo version 1.6.8_p12 is installed AND it is linked against MIT Kerberos 5 AND KRB5_ environment variables are not stripped by sudoers configuration, allowing an existing sudo user to potentially bypass authentication checks.

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

Update sudo to a version that properly validates Kerberos authentication state or configure sudo to strip KRB5_ environment variables via the env_reset option in /etc/sudoers. If Kerberos authentication via sudo is not required, rebuild sudo without MIT Kerberos 5 linkage.

Fix this in Kerberos 5 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,210
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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-2007-3149 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
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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