Detections
Analytics
6.1.3 Ensure cryptographic mechanisms are used to protect the integrity of audit tools
Information
Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators.Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity.
Attackers may replace the audit tools or inject code into the existing tools with the purpose of providing the capability to hide or erase system activity from the audit logs.
Audit tools should be cryptographically signed in order to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files.
Solution
Run the following command to determine the absolute path to the non-symlinked version on the audit tools:# readlink -f /sbin
The output will be either /usr/sbin - OR - /sbin Ensure the correct path is used.
Edit /etc/aide.conf and add or update the following selection lines replacing <PATH> with the correct path returned in the command above:
# Audit Tools
<PATH>/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512
<PATH>/auditd p+i+n+u+g+s+b+acl+xattrs+sha512
<PATH>/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512
<PATH>/aureport p+i+n+u+g+s+b+acl+xattrs+sha512
<PATH>/autrace p+i+n+u+g+s+b+acl+xattrs+sha512
<PATH>/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512
Example
# printf '
%s' "# Audit Tools" "$(readlink -f /sbin/auditctl) p+i+n+u+g+s+b+acl+xattrs+sha512"
"$(readlink -f /sbin/auditd) p+i+n+u+g+s+b+acl+xattrs+sha512"
"$(readlink -f /sbin/ausearch) p+i+n+u+g+s+b+acl+xattrs+sha512"
"$(readlink -f /sbin/aureport) p+i+n+u+g+s+b+acl+xattrs+sha512"
"$(readlink -f /sbin/autrace) p+i+n+u+g+s+b+acl+xattrs+sha512"
"$(readlink -f /sbin/augenrules) p+i+n+u+g+s+b+acl+xattrs+sha512" >> /etc/aide.conf
Note: - IF - /etc/aide.conf includes a @@x_include statement:
Example:
@@x_include /etc/aide.conf.d ^[a-zA-Z0-9_-]+$
- @@x_include FILE
- @@x_include DIRECTORY REGEX
- @x_include is identical to @@include except that if a config file is executable it is run and the output is used as config.
- If the executable file exits with status greater than zero or writes to stderr aide stops with an error.
- For security reasons DIRECTORY and each executable config file must be owned by the current user and must not be group or world-writable.
See Also
Item Details
Category: SYSTEM AND INFORMATION INTEGRITY
References: 800-53|SI-7
Plugin: Unix
Control ID: 9f9fdb4ae58a1792a80851c4ad0e08f212854a1090a396475148e8cca4472b1d