Security Policy Update?

[meyerweb#CB]

My wife's completely stock, 4.3 Sprint S3 is giving a notification of a security policy update. Anyone seen anything about this? I wonder if it's related to the Knox security bug recently discovered:

BGU Security Researchers discover Vulnerability in Samsung'??s Secure Software on the Company'??s Flagship Device Galaxy S4
Samsung Knox Security Vulnerability Uncovered in Galaxy S4 | BGR

 

[TimmyTwo2]

I've gotten the security update message before, the first time I had to accept to allow it to push updates, I got another security update maybe a week or so ago, I think it's part of how KNOX updates security settings but not a bug.

 

[jdazzr]

So what happens if I don't accept it? I got the update yesterday on my S4 and declined it. Is it necessary? How do I get it back?