[ GLSA 200406-21 ] mit-krb5: Multiple buffer overflows in krb5_aname_to_localname

[GLSA]

Gentoo Linux Security Advisory

Title: mit-krb5: Multiple buffer overflows in krb5_aname_to_localname (GLSA 200406-21)
Severity: high
Exploitable: remote
Date: June 29, 2004
Bug(s): #52744
ID: 200406-21

Synopsis


mit-krb5 contains multiple buffer overflows in the function
krb5_aname_to_localname(). This could potentially lead to a complete remote
system compromise.


Background


mit-krb5 is the free implementation of the Kerberos network authentication
protocol by the Massachusetts Institute of Technology.


Affected Packages

Package: app-crypt/mit-krb5
Vulnerable: <= 1.3.3
Unaffected: >= 1.3.3-r1
Architectures: All supported architectures


Description


The library function krb5_aname_to_localname() contains multiple buffer
overflows. This is only exploitable if explicit mapping or rules-based
mapping is enabled. These are not enabled as default.

With explicit mapping enabled, an attacker must authenticate using a
principal name listed in the explicit mapping list.

With rules-based mapping enabled, an attacker must first be able to create
arbitrary principal names either in the local realm Kerberos realm or in a
remote realm from which the local realm's service are reachable by
cross-realm authentication.


Impact


An attacker could use these vulnerabilities to execute arbitrary code with
the permissions of the user running mit-krb5, which could be the root user.


Workaround


There is no known workaround at this time. All users are encouraged to
upgrade to the latest available version.


Resolution


mit-krb5 users should upgrade to the latest version: