ZyXEL UAG715 User Guide - Page 332

Truncated-header Attack

Page 332 highlights

Chapter 27 ADP Table 125 HTTP Inspection and TCP/UDP/ICMP Decoders (continued) LABEL DESCRIPTION WEBROOT-DIRECTORYTRAVERSAL ATTACK This is when a directory traversal traverses past the web server root directory. This generates much fewer false positives than the directory option, because it doesn't alert on directory traversals that stay within the web server directory structure. It only alerts when the directory traversals go past the web server root directory, which is associated with certain web attacks. TCP Decoder BAD-LENGTH-OPTIONS ATTACK This is when a TCP packet is sent where the TCP option length field is not the same as what it actually is or is 0. This may cause some applications to crash. EXPERIMENTAL-OPTIONS ATTACK This is when a TCP packet is sent which contains non-RFC-complaint options. This may cause some applications to crash. OBSOLETE-OPTIONS ATTACK This is when a TCP packet is sent which contains obsolete RFC options. OVERSIZE-OFFSET ATTACK This is when a TCP packet is sent where the TCP data offset is larger than the payload. TRUNCATED-OPTIONS ATTACK This is when a TCP packet is sent which doesn't have enough data to read. This could mean the packet was truncated. TTCP-DETECTED ATTACK T/TCP provides a way of bypassing the standard three-way handshake found in TCP, thus speeding up transactions. However, this could lead to unauthorized access to the system by spoofing connections. UNDERSIZE-LEN ATTACK This is when a TCP packet is sent which has a TCP datagram length of less than 20 bytes. This may cause some applications to crash. UNDERSIZE-OFFSET ATTACK This is when a TCP packet is sent which has a TCP header length of less than 20 bytes.This may cause some applications to crash. UDP Decoder OVERSIZE-LEN ATTACK This is when a UDP packet is sent which has a UDP length field of greater than the actual packet length. This may cause some applications to crash. TRUNCATED-HEADER ATTACK This is when a UDP packet is sent which has a UDP datagram length of less the UDP header length. This may cause some applications to crash. UNDERSIZE-LEN ATTACK This is when a UDP packet is sent which has a UDP length field of less than 8 bytes. This may cause some applications to crash. ICMP Decoder TRUNCATED-ADDRESSHEADER ATTACK This is when an ICMP packet is sent which has an ICMP datagram length of less than the ICMP address header length. This may cause some applications to crash. TRUNCATED-HEADER ATTACK This is when an ICMP packet is sent which has an ICMP datagram length of less than the ICMP header length. This may cause some applications to crash. TRUNCATED-TIMESTAMPHEADER ATTACK This is when an ICMP packet is sent which has an ICMP datagram length of less than the ICMP Time Stamp header length. This may cause some applications to crash. 332 UAG715 User's Guide

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Chapter 27 ADP
UAG715 User’s Guide
332
WEBROOT-DIRECTORY-
TRAVERSAL ATTACK
This is when a directory traversal traverses past the web server root
directory. This generates much fewer false positives than the directory
option, because it doesn’t alert on directory traversals that stay within
the web server directory structure. It only alerts when the directory
traversals go past the web server root directory, which is associated with
certain web attacks.
TCP Decoder
BAD-LENGTH-OPTIONS
ATTACK
This is when a TCP packet is sent where the TCP option length field is not
the same as what it actually is or is 0. This may cause some applications
to crash.
EXPERIMENTAL-OPTIONS
ATTACK
This is when a TCP packet is sent which contains non-RFC-complaint
options. This may cause some applications to crash.
OBSOLETE-OPTIONS ATTACK
This is when a TCP packet is sent which contains obsolete RFC options.
OVERSIZE-OFFSET ATTACK
This is when a TCP packet is sent where the TCP data offset is larger than
the payload.
TRUNCATED-OPTIONS ATTACK
This is when a TCP packet is sent which doesn’t have enough data to
read. This could mean the packet was truncated.
TTCP-DETECTED ATTACK
T/TCP provides a way of bypassing the standard three-way handshake
found in TCP, thus speeding up transactions. However, this could lead to
unauthorized access to the system by spoofing connections.
UNDERSIZE-LEN ATTACK
This is when a TCP packet is sent which has a TCP datagram length of
less than 20 bytes. This may cause some applications to crash.
UNDERSIZE-OFFSET ATTACK
This is when a TCP packet is sent which has a TCP header length of less
than 20 bytes.This may cause some applications to crash.
UDP Decoder
OVERSIZE-LEN ATTACK
This is when a UDP packet is sent which has a UDP length field of greater
than the actual packet length. This may cause some applications to
crash.
TRUNCATED-HEADER ATTACK
This is when a UDP packet is sent which has a UDP datagram length of
less the UDP header length. This may cause some applications to crash.
UNDERSIZE-LEN ATTACK
This is when a UDP packet is sent which has a UDP length field of less
than 8 bytes. This may cause some applications to crash.
ICMP Decoder
TRUNCATED-ADDRESS-
HEADER ATTACK
This is when an ICMP packet is sent which has an ICMP datagram length
of less than the ICMP address header length. This may cause some
applications to crash.
TRUNCATED-HEADER ATTACK
This is when an ICMP packet is sent which has an ICMP datagram length
of less than the ICMP header length. This may cause some applications
to crash.
TRUNCATED-TIMESTAMP-
HEADER ATTACK
This is when an ICMP packet is sent which has an ICMP datagram length
of less than the ICMP Time Stamp header length. This may cause some
applications to crash.
Table 125
HTTP Inspection and TCP/UDP/ICMP Decoders (continued)
LABEL
DESCRIPTION