TCP Timestamp Request - Ability to Disable - PCI Compliance


#1

I am requesting this feature because our PCI Vulnerability test complains about this being in the enabled state:

TCP timestamp requests enabled
Severity: Potential Problem
Impact
A remote attacker could possibly determine the amount of time since the computer was last booted.
Resolution
TCP timestamps are generally only useful for testing, and support for them should be disabled if not needed.
To disable TCP timestamps on Linux, add the following line to the /etc/sysctl.conf file:
net.ipv4.tcp_timestamps = 0
To disable TCP timestamps on Windows, set the following registry value:
Key: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters
Value: Tcp1323Opts
Data: 0 or 1
To disable TCP timestamps on Cisco, use the following command:
no ip tcp timestamp
Where can I read more about this?
More information on TCP timestamps and round-trip time measurement is available in RFC1323 and Microsoft
Article 224829.
Technical Details
Service: https
timestamp=5457877; uptime guess=0d 15h 18m 50s


#2

This is a valid feature request, and we will discuss internally for the schedule.