Re: Question re: load balancers as a security device

[Justin Ferguson <jnferguson () gmail com>]

On Jan 22, 2008, at 8:05 AM, dan.tesch () comcast net wrote:
> In reviewing our site design I have seen that the VPN between our  
> LAN and the hosting facility permits all IP traffic in both  
> directions - effectively making these public facing servers part of  
> our LAN in my opinion.
well wait, please clarify- is VPN access required to access thus  
network segment?

> [...]
> because of the load balancers in front of the servers, the world at  
> large is not able to touch the machines and thus the potential for  
> compromise is limited.
well the thing is that at least in theory they're not directly  
addressable externally, however your load balancer forwards requests  
on to the boxes, so the attack surface exists and its not like connect  
back shells are uncommon.

Now, depending on how the load balancer works, it may normalize or  
sanity check protocol data that causes a bug to be unexploitable from  
that side of the network.

I'd be asking how, exactly, this dev came to this conclusion as it  
seems like a pretty shaky argument IMHO
>

> Thanks
>
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