Russ Allbery discovered that rssh, a restricted shell, performs insufficient checking of incoming commands, which might lead to a bypass of access restrictions.
For the stable distribution (sarge) this problem has been fixed in version 2.2.3-1.sarge.2.
For the unstable distribution (sid) this problem has been fixed in version 2.3.0-1.1.
We recommend that you upgrade your rssh package.
MD5 checksums of the listed files are available in the original advisory.