shadow: Privilege escalation
Gentoo Linux Security Advisory
||GLSA 200606-02 / shadow
||June 07, 2006
||June 07, 2006: 01
All supported architectures
A security issue in shadow allows a local user to perform certain actions
with escalated privileges.
shadow provides a set of utilities to deal with user accounts.
When the mailbox is created in useradd, the "open()" function does
not receive the three arguments it expects while O_CREAT is present,
which leads to random permissions on the created file, before fchmod()
Depending on the random permissions given to the mailbox file
which is at this time owned by root, a local user may be able to open
this file for reading or writing, or even executing it, maybe as the
There is no known workaround at this time.
All shadow users should upgrade to the latest version:
Code Listing 3.1: Resolution
# emerge --sync
# emerge --ask --oneshot --verbose ">=sys-apps/shadow-4.0.15-r2"