Connecting computers and mobile devices to Edge servers from outside exposes the network to serious risks.
While the main threat is to mobile devices as they are less controlled, connecting desktops, and especially laptops, to Skype for Business services is also risky because this requires access to the Active Directory (AD) and exposes the organization to account lockout issues.
Account lockout might be the result of:
· The user changing the Active Directory password, but not changing his computer settings
· The username (without the password) being obtained by a hacker who tried to log in several times
· The system becoming the target of DDoS, Dos and brute force attacks. Such attacks can result in an unavailable network and cause significant business damage
Skype for Business Edge server offers both NTLM and certificate-based authentication (TLS-DSK). This is particularly useful for organizations which fear the usage of credentials that are passing through the Web while using NTLM authentication.
While using certificate authentication, the Skype for Business client requests a certificate on the first authentication request made with the user’s corporate credentials (Kerberos). Once a certificate is set for the client, it is subsequently used for the ongoing authentication process.
Skype for Business Edge Access Control eliminates these threats by blocking failed attempts at the Edge server side before they reach the Active Directory.
This is done by configuring a block-failed login policy that blocks attack attempts from reaching the Active Directory. The policy includes a limited number of allowed failed attempts within a defined period.