2.1.17 Ensure web proxy server services are not in use

Information

Squid is a standard proxy server used in many distributions and environments.

Unless a system is specifically set up to act as a proxy server, it is recommended that the squid package be removed to reduce the potential attack surface.

Note: Several HTTP proxy servers exist. These should be checked and removed unless required.

Solution

Run the following commands to stop squid.service and remove the squid package:

# systemctl stop squid.service
# apt purge squid

- OR - If the squid package is required as a dependency:

Run the following commands to stop and mask the squid.service :

# systemctl stop squid.service
# systemctl mask squid.service

Impact:

There may be packages that are dependent on the squid package. If the squid package is removed, these dependent packages will be removed as well. Before removing the squid package, review any dependent packages to determine if they are required on the system.

- IF - a dependent package is required: stop and mask the squid.service leaving the squid package installed.

See Also

https://workbench.cisecurity.org/benchmarks/17045

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, 800-53|CM-7, CSCv7|9.2

Plugin: Unix

Control ID: 6d9492db591056fa523a1a8bb69b285bc2c2c587a0c763b3603545c548653b2d