sudo, when linked with MIT Kerberos 5 (krb5), does not properly check whether a user can currently authenticate to Kerberos, which allows local users to gain privileges, in a manner unintended by the sudo security model, via certain KRB5_ environment variable settings. NOTE: another researcher disputes this vulnerability, stating that the attacker must be "a user, who can already log into your system, and can already use sudo."
CVSS Severity (version 2.0):
Impact Subscore: 10.0
Exploitability Subscore: 3.9
CVSS Version 2 Metrics:
Access Vector: Locally exploitable
Access Complexity: Low
Authentication: Not required to exploit
Impact Type: Provides administrator access, Allows complete confidentiality, integrity, and availability violation; Allows unauthorized disclosure of information; Allows disruption of service
Official Statement from Red Hat (06/11/2007)
Not vulnerable. Versions of sudo package shipped with Red Hat Enterprise Linux versions 2.1, 3, 4 and 5 are linked with PAM support and never use libkrb5 authentication.
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20070607 MIT krb5: makes sudo authentication issue MUCH worse.
20070607 Re: Sudo: local root compromise with krb5 enabled
20070607 Sudo: local root compromise with krb5 enabled
Vulnerable software and versions