Hi Joshua,

A few minor things for your consideration :

10.2.3    Access to all audit trails

·         I’m not sure the best route to cover this one.  If I add a rule to watch /var/log/* for ‘wa’ actions, those logs are constantly being written to so that would be too noisy I believe. Does anyone know how I would form a rule that would fire when a file within /var/log is accessed directly by a user?  Also, if the user makes any manual changes, such as deleting a file or modifying its contents?

Ensure that only root users have access to /var/log and you are already monitoring actions of users using pam_tty_audit etc. Additionally you are sending logs to remote servers which will ensure that logs are present on the remote server even if they are deleted locally. And since user actions are being monitored, you will also be able to know that logs were modified/deleted.

10.2.7   

In addition to what you have mentioned, I am sure you are already monitoring these using a FIM like OSSEC.

Regards,

Shinoj.

Hello All,

Just thought I’d give this one more shot to see if anyone had any comments on my prior message (see below)?  Any input you have would be greatly appreciated.  I won’t bother the group any more on this topic.

Thank you!

Hello,

I was wondering if anyone had any experience putting together an auditd configuration to meet PCI DSS 10.2.x requirements?  Below are the requirements and my thoughts for each one…if anyone has anything that they have done I’d love to hear it!

10.2.2    All actions taken by any individual with root or administrative privileges

·         Enable the pam_tty_audit.so shared library in /etc/pam.d/[su/sudo/sudo-i/su-l] files.

o   USER_TTY event type will contain all commands from privileged user.

·         Add following lines to /etc/audit/rules.d/audit.rules file:

o   # Audit all actions by any individual with root or administrative privileges

o   -a exit,always -F arch=b64 -F euid=0 -S execve -k root-commands

o   -a exit,always -F arch=b32 -F euid=0 -S execve -k root-commands

§  EXECVE event type will contain all commands from user with elevated privileges.

§  Question: with the pam_tty_audit.so enabled, and those commands being logged to USER_TTY events…is this rule needed also?

10.2.3    Access to all audit trails

·         I’m not sure the best route to cover this one.  If I add a rule to watch /var/log/* for ‘wa’ actions, those logs are constantly being written to so that would be too noisy I believe. Does anyone know how I would form a rule that would fire when a file within /var/log is accessed directly by a user?  Also, if the user makes any manual changes, such as deleting a file or modifying its contents?

10.2.4    Invalid logical access attempts

·         Based on my understanding, this wouldn’t really be covered by auditd, but by the standard authpriv facility.  Anybody configure anything in auditd to cover this requirement?

10.2.5    Use of and changes to identification and authentication mechanisms—including but not limited to creation of new accounts and elevation of privileges—and all changes, additions, or deletions to accounts with root or administrative privileges

·         CRED_ACQ (sudo) and USER_AUTH (su) events should contain when a user sudo’s or su’s to privileged account.  My understanding is that these would not require any extra rules to be written.  However, I’m not quite sure how to handle the requirements to log creation of new accounts, and all changes, or deletions to accounts with root/admin privileges…any ideas?

10.2.6.   Initialization, stopping, or pausing of the audit logs

·         Auditd:

o   DAEMON_END events would indicate auditd was stopped.

o   DAEMON_START and SERVICE_START events would indicate when auditd initialized.

o   Anything else anybody would add here?

·         Rsyslog:

o   SERVICE_START event (unit=rsyslog) when rsyslog is initialized

o   SERVICE_STOP event (unit=rsyslog) when rsyslog is stopped

o   Anything else anybody would add here?

10.2.7    Creation and deletion of system- level objects

·         -w [DIRECTORY] –p wa rules for the directories below:

o   /bin

o   /sbin

o   /usr/bin

o   /usr/sbin

o   /var/lib

o   /usr/lib

o   /usr/libexec

o   /lib64

o   /usr/lib64

§  Would the above cover this requirement?  Any other suggestions here?

Joshua Ammons Advanced SIEM Engineer, Cybersecurity

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