Penetration Testing mailing list archives
Re: hash-injection/pass-the-hash countermeasure
From: natron <natron () invisibledenizen org>
Date: Thu, 20 Nov 2008 11:46:57 -0600
Two factor auth may be the solution in the theoretical sense, but in practice it isn't. Two-factor only gets you some sort of hash that then represents you. It's at that point you can steal the hash. Two factor only helps this situation if you *require* the signing capabilities of NTLM in all cases (or require kerberos in all situations), which most companies can't do for various reasons. Otherwise, the authenticated "you" still ends up being represented by a hash that can be stolen and re-used. Two factor only works on that first level, the part where you obtain the hash. Once the hash is obtained, you don't need either factor anymore (either the keyfob or the password; both have been replaced with the hash). -n On Wed, Nov 19, 2008 at 9:14 PM, Baykal, Adnan (CSCIC) <adnan.baykal () cscic state ny us> wrote:
I am sorry but can you explain how pass the hash is not defended against using the two factor authentication? in two factor authenticaion, if attacker gains access to your password hash and can inject it into the authentication process, they are still missing the second piece. I strongly believe that a two facto authentication is a solution to pass the hash issue. that is my two cents.... -------------------------------------------------------- This message may contain confidential information and is intended only for the individual(s) named. If you are not an intended recipient you are not authorized to disseminate, distribute or copy this e-mail. Please notify the sender immediately if you have received this e-mail by mistake and delete this e-mail from your system. ________________________________ From: listbounce () securityfocus com on behalf of natron Sent: Wed 11/19/2008 3:49 PM To: gum5h03 () gmail com Cc: Danny Fullerton; pen-test () securityfocus com Subject: Re: hash-injection/pass-the-hash countermeasure Multi factor auth wouldn't fix this in most environments. The 2 factor part is great for the 1st part of authentication, but then it usually has to be implemented in the protocols that are available: e.g. NTLM. Unless you use signing, that is.. but if you're using signing, you've already solved the problem. Two factor's great, but not very applicable here. Or am I missing something? n On Tue, Nov 18, 2008 at 9:57 PM, <gum> <5h03> <gum5h03 () gmail com> wrote:Multi (two) factor authentication would alleviate this and other cryptographical authentication attacks. On 11/17/08, Danny Fullerton <dfullerton () mantor org> wrote:Hello, I been aware of the hash-injection vulnerability in Windows authentication system for some time but had no opportunity to further investigate some effective countermeasures. All the information I found was oriented toward the attack rather then the exposure and effective solutions. Some proposed to restrict user from getting administrator account on there own workstation but I think there's too much canvas and exception to only consider this method. Others suggest using unique dedicated userid/passsword for every system but didn't mention any implementation detail. I guess this include a procedural control dictating the way help desk and administrators use those IDs (something enforcing proper use of the password like changing its value after each use and ensuring accountability). Some research notate that not all protocol generate "windows logon" but all of this is unclear. Which protocol really use the ?safe? Kerberos method, which will trigger an insecure "windows logon" (lm/ntml/ntmlv2) and for what reason? From my understanding "Remote Desktop" would create an unsafe "windows logon" every time, but I want to known why. I heard the best way would be to have a "Kerberos only" option in "HKEY_LOCAL_MACHINE\System\CurrentControlSet\control\LSA" among "level 5 - NTLNv2 only, level 4 - only NTLM and NTLMv2, ..." but this is only possible if you can broke compatibility with older system and this is not always possible in some environment... and by getting Microsoft to do so. How do people address this risk? Anyone have other ideas? I would like to have your inputs before undertaking my own test, if found necessary. Ref: http://truesecurity.se/blogs/murray/archive/tags/hash+injection/default.aspx thanks, --- Danny Fullerton Mantor Organization ------------------------------------------------------------------------ This list is sponsored by: Cenzic Security Trends Report from Cenzic Stay Ahead of the Hacker Curve! Get the latest Q2 2008 Trends Report now www.cenzic.com/landing/trends-report ------------------------------------------------------------------------------------------------------------------------------------------------ This list is sponsored by: Cenzic Security Trends Report from Cenzic Stay Ahead of the Hacker Curve! Get the latest Q2 2008 Trends Report now www.cenzic.com/landing/trends-report ------------------------------------------------------------------------------------------------------------------------------------------------ This list is sponsored by: Cenzic Security Trends Report from Cenzic Stay Ahead of the Hacker Curve! Get the latest Q2 2008 Trends Report now www.cenzic.com/landing/trends-report ------------------------------------------------------------------------ ------------------------------------------------------------------------ This list is sponsored by: Cenzic Security Trends Report from Cenzic Stay Ahead of the Hacker Curve! Get the latest Q2 2008 Trends Report now www.cenzic.com/landing/trends-report ------------------------------------------------------------------------
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Current thread:
- hash-injection/pass-the-hash countermeasure Danny Fullerton (Nov 17)
- Re: hash-injection/pass-the-hash countermeasure <gum> <5h03> (Nov 19)
- Re: hash-injection/pass-the-hash countermeasure natron (Nov 19)
- RE: hash-injection/pass-the-hash countermeasure Erin Carroll (Nov 19)
- Re: hash-injection/pass-the-hash countermeasure <gum> <5h03> (Nov 19)
- RE: hash-injection/pass-the-hash countermeasure Baykal, Adnan (CSCIC) (Nov 19)
- Re: hash-injection/pass-the-hash countermeasure natron (Nov 20)
- Re: hash-injection/pass-the-hash countermeasure natron (Nov 19)
- Re: hash-injection/pass-the-hash countermeasure <gum> <5h03> (Nov 19)