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author | Junio C Hamano <junio@pobox.com> | 2017-07-26 10:24:20 -0700 |
---|---|---|
committer | Junio C Hamano <gitster@pobox.com> | 2017-07-28 15:51:14 -0700 |
commit | 820d7650cc670d3e4195aad3a5343158c316e8fa (patch) | |
tree | b91d24011ab5ef19d7a671395ff0b0f9d2cce001 | |
parent | c8dd1e3bb1152844983558802a52c9e4c17652b4 (diff) | |
download | git-820d7650cc670d3e4195aad3a5343158c316e8fa.tar.gz |
connect: reject ssh hostname that begins with a dash
When commands like "git fetch" talk with ssh://$rest_of_URL/, the
code splits $rest_of_URL into components like host, port, etc., and
then spawns the underlying "ssh" program by formulating argv[] array
that has:
- the path to ssh command taken from GIT_SSH_COMMAND, etc.
- dashed options like '-batch' (for Tortoise), '-p <port>' as
needed.
- ssh_host, which is supposed to be the hostname parsed out of
$rest_of_URL.
- then the command to be run on the other side, e.g. git
upload-pack.
If the ssh_host ends up getting '-<anything>', the argv[] that is
used to spawn the command becomes something like:
{ "ssh", "-p", "22", "-<anything>", "command", "to", "run", NULL }
which obviously is bogus, but depending on the actual value of
"<anything>", will make "ssh" parse and use it as an option.
Prevent this by forbidding ssh_host that begins with a "-".
Noticed-by: Joern Schneeweisz of Recurity Labs
Reported-by: Brian at GitLab
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
-rw-r--r-- | connect.c | 3 |
1 files changed, 3 insertions, 0 deletions
@@ -754,6 +754,9 @@ struct child_process *git_connect(int fd[2], const char *url, return NULL; } + if (ssh_host[0] == '-') + die("strange hostname '%s' blocked", ssh_host); + ssh = getenv("GIT_SSH_COMMAND"); if (!ssh) { const char *base; |