Red Hat Bugzilla – Bug 1077843
CVE-2014-2532 openssh: AcceptEnv environment restriction bypass flaw
Last modified: 2014-10-17 03:56:46 EDT
Common Vulnerabilities and Exposures assigned an identifier CVE-2014-2532 to
the following vulnerability:
sshd in OpenSSH before 6.6 does not properly support wildcards on
AcceptEnv lines in sshd_config, which allows remote attackers to
bypass intended environment restrictions by using a substring located
before a wildcard character.
Created openssh tracking bugs for this issue:
Affects: fedora-all [bug 1077853]
The sshd_config file by default contain the following AcceptEnv directives.
AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
AcceptEnv LC_IDENTIFICATION LC_ALL LANGUAGE
None of the above variables contain wildcards (* or ?). This implies that the packages in their default state are not vulnerable to the above issue.
If an administrator adds environment variables to the above list (in /etc/ssh/sshd_config) which contains wildcards, than the configuration may become vulnerable.
The maximum impact of the issue is that the client may export certain environment variables to his ssh session (after authentication) which may be otherwise be restricted by the ssh server.
This issue affects the version of openssh as shipped with Red Hat Enterprise Linux 5. The Red Hat Security Response Team has rated this issue as having Low security impact. This issue is not planned to be fixed in Red Hat Enterprise Linux 5 as it is now in Production 3 Phase of the support and maintenance life cycle, https://access.redhat.com/support/policy/updates/errata/
The correct reproducer is not yet available. We agreed on IRC with Huzaifa to do only SanityOnly testing. Clearing needinfo.
openssh-6.4p1-4.fc20 has been pushed to the Fedora 20 stable repository. If problems still persist, please make note of it in this bug report.
openssh-6.2p2-8.fc19 has been pushed to the Fedora 19 stable repository. If problems still persist, please make note of it in this bug report.
It was found that OpenSSH did not properly handle certain AcceptEnv parameter values with wildcard characters. A remote attacker could use this flaw to bypass intended environment variable restrictions.
This issue has been addressed in the following products:
Red Hat Enterprise Linux 6
Via RHSA-2014:1552 https://rhn.redhat.com/errata/RHSA-2014-1552.html