Apropos of _nothing in particular_: Do you monitor or support perimeter SSL VPN portals? Have you tested various forms of successful and unsuccessful logins to see exactly what gets logged in various scenarios? If not, you may be surprised by what the system does not log.
Especially concerning would be successful authentication that does not get logged unless very specific further actions are taken, indicating that pre-auth AND post-auth RCE vulnerabilities would likely go unnoticed ( even with robust monitoring ) until you were notified by a third-party.
Good thing these security vendors produce ( er, acquire ) secure code for their security products and this is just a hypothetical thought exercise...