AIX 5.3 TL 8 : bos.net.tcp.client (U832257)
Medium Nessus Plugin ID 46470
SynopsisThe remote AIX host is missing a vendor-supplied security patch.
DescriptionThe remote host is missing AIX PTF U832257, which is related to the security of the package bos.net.tcp.client.
NTP mode 7 (MODE_PRIVATE) is used by the ntpdc query and control utility. In contrast, ntpq uses NTP mode 6 (MODE_CONTROL), while routine NTP time transfers use modes 1 through 5. Upon receipt of an incorrect mode 7 request or a mode 7 error response from an address that is not listed in a 'restrict ... noquery' or 'restrict ...
ignore' segment, ntpd will reply with a mode 7 error response and log a message.
If an attacker spoofs the source address of ntpd host A in a mode 7 response packet sent to ntpd host B, both A and B will continuously send each other error responses, for as long as those packets get through.
If an attacker spoofs an address of ntpd host A in a mode 7 response packet sent to ntpd host A, then host A will respond to itself endlessly, consuming CPU and logging excessively.
SolutionInstall the appropriate missing security-related fix.