tcpdump 3.8.3 and earlier allows remote attackers to cause a denial of service (infinite loop) via a crafted (1) BGP packet, which is not properly handled by RTROUTINGINFO, or (2) LDP packet, which is not properly handled by the ldpprint function.
The bgpupdateprint function in tcpdump 3.x does not properly handle a -1 return value from the decodeprefix4 function, which allows remote attackers to cause a denial of service (infinite loop) via a crafted BGP packet.