Linux-PAM: Privilege escalation — GLSA 200909-01

An error in the handling of user names of Linux-PAM might allow remote attackers to cause a Denial of Service or escalate privileges.

Affected Packages

sys-libs/pam on all architectures
Affected versions < 1.0.4
Unaffected versions >= 1.0.4

Background

Linux-PAM (Pluggable Authentication Modules) is an architecture allowing the separation of the development of privilege granting software from the development of secure and appropriate authentication schemes.

Description

Marcus Granado repoted that Linux-PAM does not properly handle user names that contain Unicode characters. This is related to integer signedness errors in the pam_StrTok() function in libpam/pam_misc.c.

Impact

A remote attacker could exploit this vulnerability to cause a Denial of Service. A remote authenticated attacker could exploit this vulnerability to log in to a system with the account of a user that has a similar user name, but with non-ASCII characters.

Workaround

There is no known workaround at this time.

Resolution

All Linux-PAM users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=sys-libs/pam-1.0.4"

References

Release Date
September 07, 2009

Latest Revision
September 07, 2009: 01

Severity
normal

Exploitable
remote

Bugzilla entries