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Fencer Intel
medium 6.3

CVE-2010-4020 json

MIT Kerberos 5 (aka krb5) 1.8.x through 1.8.3 does not reject RC4 key-derivation checksums, which might allow remote authenticated users to…

published 15y ago modified 4mo ago also EUVD-2010-3996

cvss
6.3
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.9%
EPSS 1.9% chance of exploitation in 30 days, percentile 80%
public exploits
0
none known

Summary

MIT Kerberos 5 (aka krb5) 1.8.x through 1.8.3 does not reject RC4 key-derivation checksums, which might allow remote authenticated users to forge a (1) AD-SIGNEDPATH or (2) AD-KDC-ISSUED signature, and possibly gain privileges, by leveraging the small key space that results from certain one-byte stream-cipher operations.

Patch / fix

  • krb5 Debian 14, Debian 13, Debian 12 1.8.3+dfsg-3

debian advisories DEBIAN-CVE-2010-4020

  • krb5 RHEL 6 1.8.2-3.el6_0.3
  • krb5-libs RHEL 6 1.8.2-3.el6_0.3
  • krb5-server RHEL 6 1.8.2-3.el6_0.3
  • krb5-server-ldap RHEL 6 1.8.2-3.el6_0.3
  • krb5-workstation RHEL 6 1.8.2-3.el6_0.3
  • krb5-pkinit-openssl RHEL 6 1.8.2-3.el6_0.3

red hat advisories RHSA-2010:0925

  • krb5 openSUSE Tumbleweed 1.15-1.1

opensuse advisories openSUSE-SU-2024:10004-1

Is CVE-2010-4020 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-2010-4020 updated cvss 3.5

krb5: krb5 may accept authdata checksums with low-entropy derived keys (MITKRB5-SA-2010-007)

  • Red Hat Enterprise Linux Desktop (v. 6) krb5 1.8.2-3.el6_0.3, krb5-libs 1.8.2-3.el6_0.3, krb5-workstation 1.8.2-3.el6_0.3, krb5-pkinit-openssl 1.8.2-3.el6_0.3 Red Hat Enterprise Linux Desktop Optional (v. 6) krb5 1.8.2-3.el6_0.3, krb5-server 1.8.2-3.el6_0.3, krb5-server-ldap 1.8.2-3.el6_0.3 Red Hat Enterprise Linux HPC Node (v. 6) krb5 1.8.2-3.el6_0.3, krb5-libs 1.8.2-3.el6_0.3 Red Hat Enterprise Linux HPC Node Optional (v. 6) krb5 1.8.2-3.el6_0.3, krb5-server 1.8.2-3.el6_0.3, krb5-server-ldap 1.8.2-3.el6_0.3, krb5-workstation 1.8.2-3.el6_0.3, krb5-pkinit-openssl 1.8.2-3.el6_0.3 Red Hat Enterprise Linux Server (v. 6) krb5 1.8.2-3.el6_0.3, krb5-libs 1.8.2-3.el6_0.3, krb5-server 1.8.2-3.el6_0.3, krb5-server-ldap 1.8.2-3.el6_0.3, krb5-workstation 1.8.2-3.el6_0.3, krb5-pkinit-openssl 1.8.2-3.el6_0.3 Red Hat Enterprise Linux Workstation (v. 6) krb5 1.8.2-3.el6_0.3, krb5-libs 1.8.2-3.el6_0.3, krb5-server 1.8.2-3.el6_0.3, krb5-server-ldap 1.8.2-3.el6_0.3, krb5-workstation 1.8.2-3.el6_0.3, krb5-pkinit-openssl 1.8.2-3.el6_0.3
    fixed: vendor fix RHSA-2010:0925
  • Red Hat Enterprise Linux 5 krb5
    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

1.92% chance of exploitation in the next 30 days, higher than 80% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 6.3 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:N/I:P/A:N

Classification

Weakness

References

Sources

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