Finding ID | Version | Rule ID | IA Controls | Severity |
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V-239184 | PHTN-67-000113 | SV-239184r816674_rule | Medium |
Description |
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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. |
STIG | Date |
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VMware vSphere 6.7 Photon OS Security Technical Implementation Guide | 2022-01-03 |
Check Text ( C-42395r675358_chk ) |
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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 (F-42354r816673_fix) |
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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 |