OneAgent security on AIX

To fully automate the monitoring of your operating systems, processes, and network interfaces, Dynatrace requires privileged access to your operating system during both installation and operation.

Note: OneAgent is tested extensively to ensure that it has minimal performance impact on your system and conforms to the highest security standards.

Permissions

Installation

OneAgent installer requires admin privileges to:

  • Add an entry for OneAgent to /etc/rc.shutdown
  • Register OneAgent service in the system's init via the mkitab command

Operation

The OneAgent requires admin privileges to:

  • Access the list of open sockets for each process.
  • Access the list of libraries loaded for each process.
  • Access the name and path of the executable file for each process.
  • Access command line parameters for each process.
  • Monitor network traffic.
  • Read application configuration files.
  • Load oneagentkmod​ kernel extension to enable automatic injection into processes

Operating system changes

  • The oneagentkmod kernel extension is loaded upon OneAgent service startup.

Files modified

  • /etc/rc.shutdown and /etc/inittab have an entry added for oneagent service.

Files added

Installation

The OneAgents installer adds the following files to your system:

  • OneAgent binaries and configuration files are saved in /opt/dynatrace/oneagent. Note that you can change the location using INSTALL_PATH parameter.

Operation

OneAgent adds the following files to your system:

  • OneAgent temporary files and runtime configuration are saved in /var/lib/dynatrace/oneagent/runtime.
  • OneAgent persistent configuration is saved in /var/lib/dynatrace/oneagent/config.
  • Large runtime data, such as memory dumps, is saved in /var/lib/dynatrace/oneagent/datastorage. Note that you can change the location of large runtime data using the DATA_STORAGE parameter.

System logs downloaded by OneAgent

OneAgent downloads certain system logs so that Dynatrace can diagnose issues that may be caused by conditions in your environment. Most often such issues are related to deep monitoring or installations run as automatic updates. System logs downloaded by OneAgent on AIX are:

  • /etc/security/limits
  • /var/adm/ras/errlog
  • /var/log/kern
  • /var/log/syslog

Globally writable directories

The OneAgent directory structure contains globally writable directories (1777 permissions). Changing these permissions by users is not supported.

OneAgent injection mechanism

Such permissions on the selected set of directories are necessary for successful OneAgent injection into the processes on the monitored hosts. When OneAgent injects into a process, the code module responsible for injection runs in the context of the original injected process. Consequently, the users under which these processes are run need to be permitted to write into the OneAgent directory structure, which is the reason for the global write permissions that allow that.

Similarly, certain log files require global write permissions (666) to allow applications running under various users to write to them.

System security

We're aware that global read and write permissions on OneAgent directories get flagged by security scan heuristics, but we can assure you that they're fully secure.

  • We keep the number of globally writable directories as limited as possible.
  • All these directories have a sticky bit set (actual permissions are 1777). Only the file's owner, the directory's owner, or the root user can modify the files in the directory. This is standard practice that makes the permissions more robust. It's also used for the /tmp directory to prevent ordinary users from deleting or moving other users' files.