Re: TLS/SSL Re-Negotiation Vulnerability [CVE-2011-1473]

2011-12-27 Thread Mounir IDRASSI

Hi,

The following blog post explains different mitigation techniques for 
this vulnerability and among them is Rate Limiting :

http://vincent.bernat.im/en/blog/2011-ssl-dos-mitigation.html#rate_limiting_ssl_handshakes

I hope this will help.
Cheers,
--
Mounir IDRASSI
IDRIX
http://www.idrix.fr

On 12/21/2011 7:40 PM, Hasan, Rezaul (NSN - US/Arlington Heights) wrote:


Hello All,

We have openssl 0.9.8r on our Linux Server. Application thats used is 
httpd.


A Nessus security scan on our Linux server tells us that we may be 
vulnerable to a potential DOS due to SSL/TLS Renegotiation 
Vulnerability [CVE-2011-1473].


The suggestions of mitigating these (we believe) are:

1. Disable Re-Negotiation completely. {We CANNOT use this choice, 
because our system does need to allow Re-Negotiation in some cases. So 
NOT an option for us}


2. Rate-Limit Re-Negotiations.

Can someone please provide detailed information/guidance about exactly 
how to go about Rate-Limiting Re-Negotiation requests on the Linux 
Server? Pointing to a detailed article would also be helpful.


Thanks a bunch in advance.



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TLS/SSL Re-Negotiation Vulnerability [CVE-2011-1473]

2011-12-21 Thread Hasan, Rezaul (NSN - US/Arlington Heights)
Hello All,

We have openssl 0.9.8r on our Linux Server. Application thats used is
httpd.

A Nessus security scan on our Linux server tells us that we may be
vulnerable to a potential DOS due to SSL/TLS Renegotiation Vulnerability
[CVE-2011-1473].

The suggestions of mitigating these (we believe) are:

1. Disable Re-Negotiation completely. {We CANNOT use this choice,
because our system does need to allow Re-Negotiation in some cases. So
NOT an option for us}

2. Rate-Limit Re-Negotiations.

Can someone please provide detailed information/guidance about exactly
how to go about Rate-Limiting Re-Negotiation requests on the Linux
Server? Pointing to a detailed article would also be helpful.

Thanks a bunch in advance.