Check: GEN003580
Title
The system must use initial TCP sequence numbers most resistant to sequence number guessing attacks. (Cat II impact)
Discussion
One use of initial TCP sequence numbers is to verify bidirectional communication between two hosts, which provides some protection against spoofed source addresses being used by the connection originator. If the initial TCP sequence numbers for a host can be determined by an attacker, it may be possible to establish a TCP connection from a spoofed source address without bidirectional communication.
Check Content
# /usr/sbin/systune tcpiss_md5 If this variable is not set or is not set to 1, this is a finding.
Fix Text
Additional Identifiers
Rule ID:
Vulnerability ID: V-12001
Group Title:
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-001436 |
The organization disables organization-defined networking protocols within the information system deemed to be nonsecure except for explicitly identified components in support of specific operational requirements. |
Controls
Number | Title |
---|---|
No controls are assigned to this check |