Title

NixOS syslog logs must have a mode of 0640 or less permissive. (Cat II impact)

Discussion

Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the NixOS system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000205-GPOS-00083

Check Content

Verify that syslog log files have a mode of "0640" or less permissive by executing the following command: $ cat $(egrep -o 'cfgfile=.*\.conf' $(nix-store --query --requisites /run/current-system | grep syslog-ng.service)/syslog-ng.service | awk -F '=' '{print $2}') | grep -w perm perm(0640); If any occurrences of "perm" are not configured as "0640" or less permissive, they are not specified, or they are commented out, this is a finding.

Fix Text

Configure the syslog-ng service to create log files with a mode of "0640" or less permissive. Note: By specifying these configurations in the "options" sections, these configurations apply globally and take effect when these configuration options are not specified later on specific file-based destinations. If there are also related configurations specified at the destination level, these will either need to be updated or removed such that the global specifications apply. Add or update the "services.syslog-ng.extraConfig" configuration in /etc/nixos/configuration.nix to include the following: services.syslog-ng.extraConfig = '' options { perm(0640); }; ''; Rebuild the NixOS configuration with the following command: $ sudo nixos-rebuild switch

Additional Identifiers

Rule ID: SV-268118r1039602_rule

Vulnerability ID: V-268118

Group Title: SRG-OS-000057-GPOS-00027

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.