1.5.3 Ensure address space layout randomization (ASLR) is enabled - /etc/sysctl.conf, /etc/sysctl.d/*

Information

Address space layout randomization (ASLR) is an exploit mitigation technique which randomly arranges the address space of key data areas of a process.

Rationale:

Randomly placing virtual memory regions will make it difficult to write memory page exploits as the memory placement will be consistently shifting.

Solution

Set the following parameter in /etc/sysctl.conf or a /etc/sysctl.d/* file:

kernel.randomize_va_space = 2

Run the following commands to comment out entries that override the default setting of kernel.randomize_va_space:

# sed -ri 's/^s*kernel.randomize_va_spaces*=s*([0-1]|[3-9]|[1-9][0-9]+)/# &/gi' /etc/sysctl.conf
# [ -e /etc/sysctl.d/* ] && sed -ri 's/^s*kernel.randomize_va_spaces*=s*([0-1]|[3-9]|[1-9][0-9]+)/# &/gi' /etc/sysctl.d/*

Run the following command to set the active kernel parameter:

# sysctl -w kernel.randomize_va_space=2

See Also

https://workbench.cisecurity.org/files/3148

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION, SYSTEM AND INFORMATION INTEGRITY

References: 800-53|SC-39, 800-53|SI-16, CSCv6|8.4, CSCv7|8.3

Plugin: Unix

Control ID: 48b7be2fc5c6ca4f167b0a44424f5694f90aee50b94d0327509aaca8fef43a28