Predictable TCP ISN in Packeteer PacketShaper Critical: Less critical Impact: Connection spoofing, DoS Where: Local network Product: Packeteer PacketShaper http://www.packetshaper.com/ Description: The TCP/IP stack of Packeteer PacketShaper is generating predictable initial sequence numbers (ISN): The sequence number is incremented by 128000 per second and by 64000 per connection. (As an example, if the current SYN/ACK ISN is 319104000 then about six seconds later the ISN is likely to be 319936000.) This allows an attacker to spoof connections from trusted clients or launch a DoS attack. This type of vulnerability has been described over ten years ago in: * CERT Advisory CA-1995-01 http://www.cert.org/advisories/CA-1995-01.html * RFC 1948 http://www.faqs.org/rfcs/rfc1948.html The vulnerability has been identified in versions 7.3.0g2 and 7.5.0g1. However, other versions may be also affected. Solution: Restrict network access to the device management interfaces Found by: nnposter