[Snort-sigs] SID 524 submission
oboyle at ...8...
Wed Mar 27 21:31:03 EST 2002
All, here's a little bit of information I scrapped together on SID 524.
If you know anything else about TCP port 0 traffic, please feel free to
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Rule: BAD TRAFFIC tcp port 0 traffic
Summary: Attackers sending packets to TCP port 0.
Impact: Little to none. There are no known operating systems that will
abend because of a packet sent to TCP port 0.
Detailed Information: These packets are generally seen with source and
destination port of zero (which is invalid) and many of the other fields
in the packet will be zero including the ACK number, the SEQ number. They
sometimes contain incorrect checksums.
Attack Scenarios: Attackers may use source and/or destination port zero to
perform reconnaissance on a network.
Ease of Attack: Extremely easy.
False Positives: None.
False Negatives: As this is easy to detect, false negatives should be minimal.
Corrective Action: Filter port 0 at your network boundary or at the host level.
Additional References: intrusions at ...473...
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