rssh: Format string vulnerability — GLSA 200410-28

rssh is vulnerable to a format string vulnerability that allows arbitrary execution of code with the rights of the connected user, thereby bypassing rssh restrictions.

Affected packages

Package 	app-shells/rssh on all architectures
Affected versions 	< 2.2.2
Unaffected versions 	>= 2.2.2

Background

rssh is a restricted shell, allowing only a few commands like scp or sftp. It is often used as a complement to OpenSSH to provide limited access to users.

Description

Florian Schilhabel from the Gentoo Linux Security Audit Team found a format string vulnerability in rssh syslogging of failed commands.

Impact

Using a malicious command, it may be possible for a remote authenticated user to execute arbitrary code on the target machine with user rights, effectively bypassing any restriction of rssh.

Workaround

There is no known workaround at this time.

Resolution

All rssh users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=app-shells/rssh-2.2.2"

References

    rssh security announcement
    CVE-2004-1628