bash security update

CentOS Errata and Security Advisory CESA-2017:1931

The bash packages provide Bash (Bourne-again shell), which is the default shell for Red Hat Enterprise Linux.

Security Fix(es):

• An arbitrary command injection flaw was found in the way bash processed the hostname value. A malicious DHCP server could use this flaw to execute arbitrary commands on the DHCP client machines running bash under specific circumstances. (CVE-2016-0634)

• An arbitrary command injection flaw was found in the way bash processed the SHELLOPTS and PS4 environment variables. A local, authenticated attacker could use this flaw to exploit poorly written setuid programs to elevate their privileges under certain circumstances. (CVE-2016-7543)

• A denial of service flaw was found in the way bash handled popd commands. A poorly written shell script could cause bash to crash resulting in a local denial of service limited to a specific bash session. (CVE-2016-9401)

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 7.4 Release Notes linked from the References section.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-cr-announce/2017-August/030281.html

Affected packages:
bash
bash-doc

Upstream details at:
https://access.redhat.com/errata/RHSA-2017:1931