rssh 2.3.2, as used by Debian, Fedora, and others, when the rsync protocol is enabled, allows local users to bypass intended restricted shell access via a (1) "-e" or (2) "--" command line option.
https://exchange.xforce.ibmcloud.com/vulnerabilities/80334
https://bugzilla.redhat.com/show_bug.cgi?id=877279
http://www.securityfocus.com/bid/56708
http://www.openwall.com/lists/oss-security/2012/11/27/15
http://www.debian.org/security/2012/dsa-2578
http://secunia.com/advisories/51307
http://archives.neohapsis.com/archives/bugtraq/2012-11/0101.html