The SUSE operating system must generate error messages that provide information necessary for corrective actions without revealing information that could be exploited by adversaries.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-234832	SLES-15-010340	SV-234832r880884_rule		Medium

Description
Any operating system providing too much information in error messages risks compromising the data and security of the structure, and content of error messages needs to be carefully considered by the organization. Organizations carefully consider the structure/content of error messages. The extent to which information systems are able to identify and handle error conditions is guided by organizational policy and operational requirements. Information that could be exploited by adversaries includes, for example, erroneous logon attempts with passwords entered by mistake as the username, mission/business information that can be derived from (if not stated explicitly by) information recorded, and personal information, such as account numbers, social security numbers, and credit card numbers. The /var/log/btmp, /var/log/wtmp, and /var/log/lastlog files have group write and global read permissions to allow for the lastlog function to perform. Limiting the permissions beyond this configuration will result in the failure of functions that rely on the lastlog database.

Description

Any operating system providing too much information in error messages risks compromising the data and security of the structure, and content of error messages needs to be carefully considered by the organization. Organizations carefully consider the structure/content of error messages. The extent to which information systems are able to identify and handle error conditions is guided by organizational policy and operational requirements. Information that could be exploited by adversaries includes, for example, erroneous logon attempts with passwords entered by mistake as the username, mission/business information that can be derived from (if not stated explicitly by) information recorded, and personal information, such as account numbers, social security numbers, and credit card numbers. The /var/log/btmp, /var/log/wtmp, and /var/log/lastlog files have group write and global read permissions to allow for the lastlog function to perform. Limiting the permissions beyond this configuration will result in the failure of functions that rely on the lastlog database.

STIG	Date
SUSE Linux Enterprise Server 15 Security Technical Implementation Guide	2023-09-08

Details

Check Text ( C-38020r880882_chk )
Verify the SUSE operating system has all system log files under the /var/log directory with a permission set to "640", by using the following command: Note: The btmp, wtmp, and lastlog files are excluded. Refer to the Discussion for details. > sudo find /var/log -perm /137 ! -name '[bw]tmp' ! -name 'lastlog' -type f -exec stat -c "%n %a" {} \; If command displays any output, this is a finding.

Check Text ( C-38020r880882_chk )

Verify the SUSE operating system has all system log files under the /var/log directory with a permission set to "640", by using the following command:

Note: The btmp, wtmp, and lastlog files are excluded. Refer to the Discussion for details.

> sudo find /var/log -perm /137 ! -name '*[bw]tmp' ! -name '*lastlog' -type f -exec stat -c "%n %a" {} \;

If command displays any output, this is a finding.

Fix Text (F-37983r880883_fix)
Configure the SUSE operating system to set permissions of all log files under /var/log directory to "640" or more restricted, by using the following command: Note: The btmp, wtmp, and lastlog files are excluded. Refer to the Discussion for details. > sudo find /var/log -perm /137 ! -name '[bw]tmp' ! -name 'lastlog' -type f -exec chmod 640 '{}' \;