WebApp Sec mailing list archives
Re: yahoo mail login security
From: "Sels, Roger" <roger.sels () gov-fbi net>
Date: Tue, 2 May 2006 23:03:33 +0200 (CEST)
1. Realistically this wouldn't add an extra layer of security, but rather an obfuscation layer. Now I know a lot of people will disagree, and in my defense, I'll say it's obviously better to send the MD5 hash over SSL than over plain HTTP. This said, once a MITM attack is succesfully carried out on the unsuspecting victim, it falls pray to the same replay attacks which caused Yahoo to move away from the MD5 hash to start with. 2. Sessions are recognized through a series of cookies set by hotmail. Sniffing the URL someone is using to access their hotmail account will not gain you access to that mailbox. I don't see why non-SSL content couldn't be mixed with SSL-protected content, but I don't really see a point in encrypting those communications anyways. It's a free, public e-mail service. You know up front what you are getting. Also consider it really helps local law enforcement agencies: it makes it easier to monitor e-mail conversations as the technically clueless reveals his master plans for world domination using hotmail or when thieves discuss the genuinity of a stolen Rembrandt based on pictures they put on their MSN Space... ;-) 3. Not me, sorry. Kr Roger On Tue, May 2, 2006 8:00 am, Ace123 wrote:
1. Would it then be wise to send the md5 hash over ssl? 2. Yahoo is not alone in switching to http for email after authenticating the user, both hotmail and gmail do the same. One reason I can think of why they do this is, the various resources in their pages come from different domains (possibly 3rd party) and they can't ask for all of them to do SSL. Do you know of any other reasons? 3. The cookie names these guys use are very tricky, there are usually many cookies and it is not clear why of them represents the session, so that we can take that cookie, set it in our browser and check out other's email. Ofcourse, it might be possible to set all the cookies that we see there, but I have not tried that. Has anyone done any research on what each of the cookies is used for, in yahoo/hotmail/gmail? Thanks! On 5/2/06, ROB DIXON <rdixon () workforcewv org> wrote:exactly Robert L. Dixon, CHFI State of West Virginia's West Virginia Office of Technology Infrastructure Applications Netware/GroupWise Administrator Telephone: (304)-558-5472 ex.4225 ------------------------------------------ If you spend more on coffee than on IT security, you will be hacked. What's more, you deserve to be hacked. -- former White House cybersecurity czar Richard Clarke"Matt Fisher" <mfisher () spidynamics com> >>>Don't they revert back to HTTP after auth anyhow ? Protect my credentials all you want, but if you give up my email on the wire(less) I'm switching regardless. -----Original Message----- From: ROB DIXON [mailto:rdixon () workforcewv org] Sent: Monday, May 01, 2006 3:51 PM To: flace9 () gmail com; vanderaj () greebo net Cc: webappsec () securityfocus com Subject: Re: yahoo mail login security If you are capturing the form submission via MITM then would SSL not be just as trivial via Cain and Able.\ Granted it would be obvious since the SSL cert would appear to be invalid, but not everyone is that savy. Robert L. Dixon, CHFI State of West Virginia's West Virginia Office of Technology Infrastructure Applications Netware/GroupWise Administrator Telephone: (304)-558-5472 ex.4225 ------------------------------------------ If you spend more on coffee than on IT security, you will be hacked. What's more, you deserve to be hacked. -- former White House cybersecurity czar Richard ClarkeAndrew van der Stock <vanderaj () greebo net> >>>Several reasons: 1. MD5 does protect the password... as long as it is salted correctly. Unsalted MD5 hashes are trivially breakable using rainbow attacks, and are unsuitable for most uses (despite heavy usage by many programs in exactly this fashion). 2. Replay attacks on public networks. Capturing the form submission (trivial without SSL) would allow an attacker to replay the conversation and log on as the identity without any issues 3. MD5 is provably weak as a hash - see the work of Wang et al: http://eprint.iacr.org/2004/199.pdf 4. Javascript on the client is not a trusted environment. Minimizing the trust of security weak components is a good design goal. 5. SSL is cheap. A certificate costs less than $100 these days and solves many of these issues. Andrew On 30/04/2006, at 5:55 PM, Ace123 wrote:Clicking on "Why this is secure" link on the yahoo login page gives this: "Yahoo! now submits your ID and password securely via SSL (Secure Sockets Layer) encryption. This means that your personal information is more secure every time you sign in. In the past, Yahoo! used a challenge-response mechanism to protect passwords using MD5. Passwords were scrambled using a one-way hash, so that they could not be converted to clear text." What could be the reasons why yahoo changed their login security mechanism? ------------------------------------------------------------------------- Sponsored by: Watchfire Watchfire's AppScan is the industry's first and leading web application security testing suite, and the only solution to provide comprehensive remediation tasks at every level of the application. Change the way you think about application security testing - See for yourself. 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Current thread:
- yahoo mail login security Ace123 (Apr 30)
- Re: yahoo mail login security Andrew van der Stock (May 01)
- <Possible follow-ups>
- Re: yahoo mail login security ROB DIXON (May 01)
- RE: yahoo mail login security Matt Fisher (May 01)
- Re: yahoo mail login security Ace123 (May 01)
- Re: yahoo mail login security Sels, Roger (May 03)
- Re: yahoo mail login security Ace123 (May 03)
- Re: yahoo mail login security Sels, Roger (May 03)
- Re: yahoo mail login security Sels, Roger (May 03)
- Re: Re: yahoo mail login security Damon Leung (May 03)
- Re: Re: yahoo mail login security Darren Bounds (May 04)
- Re: Re: yahoo mail login security Prakash Kailasa (May 05)
- Re: Re: yahoo mail login security Darren Bounds (May 05)
- Re: Re: yahoo mail login security Darren Bounds (May 04)