OpenSSH before 2.9.9, when running sftp using sftp-server and using restricted keypairs, allows remote authenticated users to bypass authorized_keys2 command= restrictions using sftp commands.
https://exchange.xforce.ibmcloud.com/vulnerabilities/7634
http://www.redhat.com/support/errata/RHSA-2001-154.html
http://download.immunix.org/ImmunixOS/7.0/updates/IMNX-2001-70-034-01
http://distro.conectiva.com.br/atualizacoes/?id=a&anuncio=000431
http://archives.neohapsis.com/archives/bugtraq/2001-09/0153.html