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Fencer Intel
low 2.1

CVE-2010-4021 json

The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.7 does not properly restrict the use of TGT credentials for armoring TGS r…

published 15y ago modified 4mo ago also EUVD-2010-3997

cvss
2.1
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.1%
EPSS 2.1% chance of exploitation in 30 days, percentile 81%
public exploits
0
none known

Summary

The Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.7 does not properly restrict the use of TGT credentials for armoring TGS requests, which might allow remote authenticated users to impersonate a client by rewriting an inner request, aka a "KrbFastReq forgery issue."

Patch / fix

  • krb5 Debian 14, Debian 13, Debian 12 1.8+dfsg~alpha1-1

debian advisories DEBIAN-CVE-2010-4021

  • krb5 openSUSE Tumbleweed 1.15-1.1

opensuse advisories openSUSE-SU-2024:10004-1

Is CVE-2010-4021 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2010-4021 updated cvss 2.1

krb5: KDC may issue unrequested tickets due to KrbFastReq forgery (MITKRB5-SA-2010-007)

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.09% chance of exploitation in the next 30 days, higher than 81% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 2.1 AV:N/AC:H/Au:S/C:N/I:P/A:N

Classification

Weakness
  • CWE-16 Configuration
  • CWE-264 Permissions, Privileges, and Access Controls

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.