Debian Long Term Support / LTS Security Information / 2016 / Security Information -- DLA-468-1 libuser

Debian Security Advisory

DLA-468-1 libuser -- LTS security update

Date Reported:

12 May 2016

Affected Packages:

libuser

Vulnerable:

Yes

Security database references:

In the Debian bugtracking system: Bug 793465.
In Mitre's CVE dictionary: CVE-2015-3245, CVE-2015-3246.

More information:

Two security vulnerabilities were discovered in libuser, a library that implements a standardized interface for manipulating and administering user and group accounts, that could lead to a denial of service or privilege escalation by local users.

• CVE-2015-3245

  Incomplete blacklist vulnerability in the chfn function in libuser before 0.56.13-8 and 0.60 before 0.60-7, as used in the userhelper program in the usermode package, allows local users to cause a denial of service (/etc/passwd corruption) via a newline character in the GECOS field.

• CVE-2015-3246

  libuser before 0.56.13-8 and 0.60 before 0.60-7, as used in the userhelper program in the usermode package, directly modifies /etc/passwd, which allows local users to cause a denial of service (inconsistent file state) by causing an error during the modification. NOTE: this issue can be combined with CVE-2015-3245 to gain privileges.

In addition the usermode package, which depends on libuser, was rebuilt against the updated version.

For Debian 7 Wheezy, these problems have been fixed in

libuser 1:0.56.9.dfsg.1-1.2+deb7u1 usermode 1.109-1+deb7u2

We recommend that you upgrade your libuser and usermode packages.