Ensure Address space layout randomization is enabled

MediumLevel 1Automatedaix

Description

Address space layout randomization (ASLR) is an exploit mitigation technique which randomly arranges the address space of key data areas of a process. The recommendations here are focused on a system level rather than enterprise. The controls mention both user and administrator accounts. For the purpose of this benchmark, and account is administrator when the AIX user attribute admin is true. Audit: automated read-only check derived from the CIS audit procedure; it prints "compliant" when the control is met.

How it is checked

Audit method: Shell command

shell

command -v vmo >/dev/null 2>&1 || exit 1; out=$(vmo -aF 2>/dev/null) || exit 1; r=compliant; for p in '^[[:blank:]]*aslr[[:blank:]]*=[[:blank:]]*2$' '^[[:blank:]]*aslr32[[:blank:]]*=[[:blank:]]*"?0"?$' '^[[:blank:]]*aslr64[[:blank:]]*=[[:blank:]]*"?0"?$' '^[[:blank:]]*aslr32r[[:blank:]]*=[[:blank:]]*333$' '^[[:blank:]]*aslr64r[[:blank:]]*=[[:blank:]]*33333$' '^[[:blank:]]*aslr_r[[:blank:]]*=[[:blank:]]*0$'; do printf '%s\n' "$out" | grep -Eq -- "$p" || r="missing: $p"; done; echo "$r"

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Run the following command to enable ASLR for all programs: # /usr/sbin/vmo -r -o aslr=2 -o aslr32=0 -o aslr32r=333 -o aslr64=0 -o aslr64r=33333 -o alsr_r=0 A reboot is required before this change takes effect.

Properties

Operating systems: Any
Tags: aixhardening
Reference: CIS IBM AIX 7 Benchmark v1.2.0 - 4.9.1 Ensure Address space layout randomization is enabled

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target aix