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Fencer Intel
medium 5.0

CVE-2011-0281 json

The unparse implementation in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.6.x through 1.9, when an LDAP backend is use…

published 2011-02-10 15 y ago modified 2026-06-16 4 mo ago also EUVD-2011-0307

cvss
5.0
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.2%
EPSS 4.2% chance of exploitation in 30 days, percentile 91%
public exploits
0
none known

Summary

The unparse implementation in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) 1.6.x through 1.9, when an LDAP backend is used, allows remote attackers to cause a denial of service (file descriptor exhaustion and daemon hang) via a principal name that triggers use of a backslash escape sequence, as demonstrated by a \n sequence.

Patch / fix

  • mit kerberos_5 1.9.1
  • mit krb5 1.9.1
  • krb5 Debian 14, Debian 13, Debian 12 1.8.3+dfsg-5

debian advisories DEBIAN-CVE-2011-0281

  • krb5 RHEL 6 1.8.2-3.el6_0.4
  • krb5-libs RHEL 6 1.8.2-3.el6_0.4
  • krb5-server RHEL 6 1.8.2-3.el6_0.4
  • krb5-server-ldap RHEL 6 1.8.2-3.el6_0.4
  • krb5-workstation RHEL 6 1.8.2-3.el6_0.4
  • krb5-pkinit-openssl RHEL 6 1.8.2-3.el6_0.4
  • krb5 RHEL 5 1.6.1-55.el5_6.1
  • krb5-libs RHEL 5 1.6.1-55.el5_6.1

red hat advisories RHSA-2011:0200RHSA-2011:0199

  • krb5 openSUSE Tumbleweed 1.15-1.1

opensuse advisories openSUSE-SU-2024:10004-1

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-2011-0281 updated cvss 5.0

krb5: KDC hang when using LDAP backend caused by special principal name (MITKRB5-SA-2011-002)

  • Red Hat Enterprise Linux (v. 5.6.z server) krb5 1.6.1-55.el5_6.1, krb5-libs 1.6.1-55.el5_6.1, krb5-server 1.6.1-55.el5_6.1, krb5-server-ldap 1.6.1-55.el5_6.1, krb5-workstation 1.6.1-55.el5_6.1
    fixed: vendor fix RHSA-2011:0199
  • Red Hat Enterprise Linux Desktop (v. 6) krb5 1.8.2-3.el6_0.4, krb5-libs 1.8.2-3.el6_0.4, krb5-workstation 1.8.2-3.el6_0.4, krb5-pkinit-openssl 1.8.2-3.el6_0.4 Red Hat Enterprise Linux Desktop Optional (v. 6) krb5 1.8.2-3.el6_0.4, krb5-server 1.8.2-3.el6_0.4, krb5-server-ldap 1.8.2-3.el6_0.4 Red Hat Enterprise Linux HPC Node (v. 6) krb5 1.8.2-3.el6_0.4, krb5-libs 1.8.2-3.el6_0.4 Red Hat Enterprise Linux HPC Node Optional (v. 6) krb5 1.8.2-3.el6_0.4, krb5-server 1.8.2-3.el6_0.4, krb5-server-ldap 1.8.2-3.el6_0.4, krb5-workstation 1.8.2-3.el6_0.4, krb5-pkinit-openssl 1.8.2-3.el6_0.4 Red Hat Enterprise Linux Server (v. 6) krb5 1.8.2-3.el6_0.4, krb5-libs 1.8.2-3.el6_0.4, krb5-server 1.8.2-3.el6_0.4, krb5-server-ldap 1.8.2-3.el6_0.4, krb5-workstation 1.8.2-3.el6_0.4, krb5-pkinit-openssl 1.8.2-3.el6_0.4 Red Hat Enterprise Linux Workstation (v. 6) krb5 1.8.2-3.el6_0.4, krb5-libs 1.8.2-3.el6_0.4, krb5-server 1.8.2-3.el6_0.4, krb5-server-ldap 1.8.2-3.el6_0.4, krb5-workstation 1.8.2-3.el6_0.4, krb5-pkinit-openssl 1.8.2-3.el6_0.4
    fixed: vendor fix RHSA-2011:0200
  • Red Hat Enterprise Linux 4 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

4.20% chance of exploitation in the next 30 days, higher than 91% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Classification

Weakness

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.

CPEs and fixed versions use Anchore's correction of NVD's data: Improve kerberos 5 affected range consistency.