1 hour, 9 minutes, and 0 seconds
|Daniel P. Berrange||e4cb850 Changeset →|
|rpc: avoid ssh interpreting malicious hostname as arguments
Inspired by the recent GIT / Mercurial security flaws
consider someone/something manages to feed libvirt a bogus
URI such as:
virsh -c qemu+ssh://-oProxyCommand=gnome-calculator/system
In this case, the hosname "-oProxyCommand=gnome-calculator"
will get interpreted as an argument to ssh, not a hostname.
Fortunately, due to the set of args we have following the
hostname, SSH will then interpret our bit of shell script
that runs 'nc' on the remote host as a cipher name, which is
clearly invalid. This makes ssh exit during argv parsing and
so it never tries to run gnome-calculator.
We are lucky this time, but lets be more paranoid, by using
'--' to explicitly tell SSH when it has finished seeing
command line options. This forces it to interpret
"-oProxyCommand=gnome-calculator" as a hostname, and thus
see a fail from hostname lookup.
Signed-off-by: Daniel P. Berrange <berrange redhat com>