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Shadow: Privilege escalation


1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 200903-24 / shadow
Release Date March 10, 2009
Latest Revision March 10, 2009: 01
Impact high
Exploitable local
Package Vulnerable versions Unaffected versions Architecture(s)
sys-apps/shadow < >= All supported architectures

Related bugreports: #251320


An insecure temporary file usage in Shadow may allow local users to gain root privileges.

2.  Impact Information


Shadow is a set of tools to deal with user accounts.


Paul Szabo reported a race condition in the "login" executable when setting up tty permissions.


A local attacker belonging to the "utmp" group could use symlink attacks to overwrite arbitrary files and possibly gain root privileges.

3.  Resolution Information


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.  References


Page updated March 10, 2009

Summary: This is a Gentoo Linux Security Advisory

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