Ubuntu Security Notice USN-1233-1
18th October, 2011
krb5 vulnerabilities
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 11.10
- Ubuntu 11.04
- Ubuntu 10.10
- Ubuntu 10.04 LTS
Summary
Several denial of service issues were fixed in the Kerberos Key Distribution Center (KDC).
Software description
- krb5 - MIT Kerberos Network Authentication Protocol
Details
Nalin Dahyabhai, Andrej Ota and Kyle Moffett discovered a NULL
pointer dereference in the KDC LDAP backend. An unauthenticated
remote attacker could use this to cause a denial of service. This
issue affected Ubuntu 11.10. (CVE-2011-1527)
Mark Deneen discovered that an assert() could be triggered in the
krb5_ldap_lockout_audit() function in the KDC LDAP backend and
the krb5_db2_lockout_audit() function in the KDC DB2 backend. An
unauthenticated remote attacker could use this to cause a denial of
service. (CVE-2011-1528)
It was discovered that a NULL pointer dereference could occur in the
lookup_lockout_policy() function in the KDC LDAP and DB2 backends.
An unauthenticated remote attacker could use this to cause a denial of
service. (CVE-2011-1529)
Update instructions
The problem can be corrected by updating your system to the following package version:
- Ubuntu 11.10:
- krb5-kdc-ldap 1.9.1+dfsg-1ubuntu1.1
- krb5-kdc 1.9.1+dfsg-1ubuntu1.1
- Ubuntu 11.04:
- krb5-kdc-ldap 1.8.3+dfsg-5ubuntu2.2
- krb5-kdc 1.8.3+dfsg-5ubuntu2.2
- Ubuntu 10.10:
- krb5-kdc-ldap 1.8.1+dfsg-5ubuntu0.8
- krb5-kdc 1.8.1+dfsg-5ubuntu0.8
- Ubuntu 10.04 LTS:
- krb5-kdc-ldap 1.8.1+dfsg-2ubuntu0.10
- krb5-kdc 1.8.1+dfsg-2ubuntu0.10
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.