Detections
Analytics

4.1.2.7 Ensure audit_backlog_limit is sufficient

Warning! Audit Deprecated

This audit has been deprecated and will be removed in a future update.

View Next Audit Version

Information

The backlog limit has a default setting of 64

During boot if audit=1, then the backlog will hold 64 records. If more than 64 records are created during boot, auditd records will be lost and potential malicious activity could go undetected.

Solution

Edit /etc/default/grub and add audit_backlog_limit=<BACKLOG SIZE> to GRUB_CMDLINE_LINUX:

Example:

GRUB_CMDLINE_LINUX="audit_backlog_limit=8192"

Run the following script to update the grub2 configuration:

#!/usr/bin/env bash

GFCU()
{
 grubfile=$(find /boot -type f \( -name 'grubenv' -o -name 'grub.conf' -o -name 'grub.cfg' \) -exec grep -Pl '^\h*(kernelopts=|linux|kernel)' {} \;)
 grubdir=$(dirname "$grubfile")
 grub2-mkconfig -o "$grubdir/grub.cfg"
}
GFCU

See Also

https://workbench.cisecurity.org/benchmarks/8415

Item Details

References: CSCv7|6.2, CSCv7|6.3

Plugin: Unix

Control ID: eb0f03ede7d9631a535c2fd25a0ad301d4b68f7e91659b4e941040b623524036