Full Disclosure mailing list archives
Re: OpenSSH User Enumeration Time-Based Attack
From: Curesec Research Team <crt () curesec com>
Date: Fri, 12 Jul 2013 20:07:11 +0100
Am 11.07.2013 16:41, schrieb Jann Horn:
FYI, the openssh guys have known this for quite a while and they don't treat it as an issue worth fixing. They don't want to introduce extra anti-timing code just to prevent user enumeration from working.
Oh really?
By the way: If you can hog the CPU for seconds by sending a few kilobytes of data, isn't that a DoS issue?
Yes, you can raise the cpu usage massively. So you can definitly slow down the system. Maybe it is possible with some more threads to increase as well memory usage. Of course you have to constantly sending ssh authentication messages to the target system to hold up the cpu consumption. Cheers, _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
Current thread:
- OpenSSH User Enumeration Time-Based Attack Curesec Research Team (Jul 10)
- Re: OpenSSH User Enumeration Time-Based Attack Jason Hellenthal (Jul 10)
- Re: OpenSSH User Enumeration Time-Based Attack Swair Mehta (Jul 10)
- Re: OpenSSH User Enumeration Time-Based Attack Jann Horn (Jul 11)
- Re: OpenSSH User Enumeration Time-Based Attack Curesec Research Team (Jul 13)
- Re: OpenSSH User Enumeration Time-Based Attack Florian Reinholz (Jul 13)
- Re: OpenSSH User Enumeration Time-Based Attack Grandma Eubanks (Jul 13)
- <Possible follow-ups>
- Re: OpenSSH User Enumeration Time-Based Attack security curmudgeon (Jul 13)