mailing list archives
Re: [ GLSA 200411-09 ] shadow: Unauthorized modification of account information
From: Solar Designer <solar () openwall com>
Date: Fri, 5 Nov 2004 00:57:26 +0300
On Thu, Nov 04, 2004 at 09:22:24PM +0100, Matthias Geerdsen wrote:
Title: shadow: Unauthorized modification of account information
A flaw in the chfn and chsh utilities might allow modification of
account properties by unauthorized users.
A local attacker may be able to use chfn and chsh to change the
standard shell of other users or modify their GECOS information (full
name, phone number...).
While you did correctly categorize this as "low" severity, the above
description is not correct. It is not possible to use this on other
users' accounts. Here's the description from Owl change log:
2004/06/09 Package: shadow-utils
SECURITY FIX Severity: none to low, local, active
Properly check the return value from pam_chauthtok(3) in chfn(1) and
chsh(1). Previously, if chfn and/or chsh commands would be enabled
for non-privileged users with control(8), it would have been possible
for a logged in user with an expired password to change their "Full
Name" and login shell without having to change the password. Thanks
to Steve Grubb and Martin Schulze for discovering this problem.
The only bug here is that chfn/chsh did not properly force a change of
an expired password, yet permitted the requested change of GECOS info
or login shell to be performed. This is hardly worth an advisory. In
fact, it might not have been worth our change log entry either...
Alexander Peslyak <solar at openwall.com>
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