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V-271748

CAT II (Medium)

OL 9 must disable access to network bpf system call from nonprivileged processes.

Rule ID

SV-271748r1117266_rule

STIG

Oracle Linux 9 Security Technical Implementation Guide

Version

V1R5

CCIs

CCI-001082

Discussion

Loading and accessing the packet filters programs and maps using the bpf() system call has the potential of revealing sensitive information about the kernel state.

Check Content

Verify that OL 9 prevents privilege escalation thru the kernel by disabling access to the bpf system call with the following commands:

$ sysctl kernel.unprivileged_bpf_disabled
kernel.unprivileged_bpf_disabled = 1

If the returned line does not have a value of "1", or a line is not returned, this is a finding.

Fix Text

Configure OL 9 to prevent privilege escalation thru the kernel by disabling access to the bpf syscall by adding the following line to a file, in the "/etc/sysctl.d" directory:

kernel.unprivileged_bpf_disabled = 1

The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command:

$ sudo sysctl --system