From: Anderson Toshiyuki Sasaki Date: Wed, 19 Sep 2018 14:30:33 +0200 Subject: [5/8] CVE-2018-10933: Check channel state when OPEN_CONFIRMATION arrives Origin: https://git.libssh.org/projects/libssh.git/commit/?id=3837a0547f08b160749fed7496316a62d6c11dea Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2018-10933 Bug-Debian: https://bugs.debian.org/911149 When a SSH2_MSG_OPEN_CONFIRMATION arrives, the channel state is checked to be in SSH_CHANNEL_STATE_OPENING. Fixes T101 Signed-off-by: Anderson Toshiyuki Sasaki --- src/channels.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/src/channels.c b/src/channels.c index 30c314683c9b..d5d36af5ead2 100644 --- a/src/channels.c +++ b/src/channels.c @@ -170,6 +170,15 @@ SSH_PACKET_CALLBACK(ssh_packet_channel_open_conf){ "Received a CHANNEL_OPEN_CONFIRMATION for channel %d:%d", channel->local_channel, channel->remote_channel); + + if (channel->state != SSH_CHANNEL_STATE_OPENING) { + SSH_LOG(SSH_LOG_RARE, + "SSH2_MSG_CHANNEL_OPEN_CONFIRMATION received in incorrect " + "channel state %d", + channel->state); + goto error; + } + SSH_LOG(SSH_LOG_PROTOCOL, "Remote window : %lu, maxpacket : %lu", (long unsigned int) channel->remote_window, -- 2.19.1