Check: PHTN-67-000113
VMware vSphere 6.7 Photon OS STIG:
PHTN-67-000113
(in versions v1 r6 through v1 r1)
Title
The Photon operating system must send TCP timestamps. (Cat II impact)
Discussion
TCP timestamps are used to provide protection against wrapped sequence numbers. It is possible to calculate system uptime (and boot time) by analyzing TCP timestamps. These calculated uptimes can help a bad actor in determining likely patch levels for vulnerabilities.
Check Content
At the command line, execute the following command: # /sbin/sysctl -a --pattern "net.ipv4.tcp_timestamps$" Expected result: net.ipv4.tcp_timestamps = 1 If the output does not match the expected result, this is a finding.
Fix Text
Open /etc/sysctl.conf with a text editor. Add or update the following line: net.ipv4.tcp_timestamps = 1 Run the following command to load the new setting: # /sbin/sysctl --load
Additional Identifiers
Rule ID: SV-239184r816674_rule
Vulnerability ID: V-239184
Group Title: SRG-OS-000480-GPOS-00227
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-000366 |
The organization implements the security configuration settings. |
Controls
Number | Title |
---|---|
CM-6 |
Configuration Settings |