Full Disclosure mailing list archives
RE: TinyURL
From: "David Klotz" <klotz () acm org>
Date: Wed, 29 Oct 2003 08:30:17 -0600
I don't agree. First, you shouldn't be using a service like this to send sensitive information in the first place, and if you are, you get what you deserve. If I leave my bank account number in my mailbox so I'll know where to get it, I shouldn't blame the post office if someone comes along and steals it. Second, the whole idea behind tinyurl is to take long, difficult to type URLs and change them into something much easier. In order for them to generate a string that was long enough so that the chance of someone randomly guessing another valid string is low, they would have to use a string so long that it would only be marginally easier to type or send than the original URL it was designed to replace... Just my 2 cents... -dk
-----Original Message----- From: full-disclosure-admin () lists netsys com [mailto:full-disclosure-admin () lists netsys com] On Behalf Of Joel R. Helgeson Sent: Wednesday, October 29, 2003 5:19 AM To: full-disclosure () netsys com Subject: [Full-disclosure] TinyURL This is an information leak rather than a real vulnerability. I thought it might be of interest to others...
www.tinyurl.com is a website that will convert a long url to a short one. If you want to email a link to say, driving directions on mapquest, the url is rather long and will get broken up. Tinyurl will store that long link, and give you a short one that looks like: http://tinyurl.com/abcd It appears that the last four letters are incremented one letter at a time, so my URL may be aaaa, then aaab, and so forth. If people are using the tiny URL service to pass along URL's to sensitive information, it is easy to guess these URL's. I recently sent an email to someone with a tinyurl, and decided to change one character in the url and came across a link to a kiddie porn site... http://tinyurl.com/stab Its a coincidence that stab is a word, but its just a few characters off from my URL, staa & stac are also valid URL's. The TinyURL service should use a randomly created string, rather than one that is incremented by one character. Regardless, users of this service could have the information they intend to share with others viewed by anyone that types in the string. Thoughts? Joel R. Helgeson Director of Networking & Security Services SymetriQ Corporation "Give a man fire, and he'll be warm for a day; set a man on fire, and he'll be warm for the rest of his life." _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.netsys.com/full-disclosure-charter.html _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.netsys.com/full-disclosure-charter.html
Current thread:
- TinyURL Joel R. Helgeson (Oct 29)
- Re: TinyURL Thomas Springer (Oct 29)
- Re: TinyURL Kenton Smith (Oct 29)
- RE: TinyURL Ricky Blaikie (Oct 29)
- Re: TinyURL Joel R. Helgeson (Oct 29)
- Re: TinyURL Martin Schuster (Oct 30)
- Re: TinyURL Josh (Oct 30)
- <Possible follow-ups>
- RE: TinyURL David Klotz (Oct 29)
- Re: TinyURL Troy (Oct 29)
- Re: TinyURL Joel R. Helgeson (Oct 29)
- Re: TinyURL Troy (Oct 29)
- Re: TinyURL Helge Oldach (Oct 29)
- Re: TinyURL Troy (Oct 29)
- RE: TinyURL Bassett, Mark (Oct 29)
- Re: TinyURL John Sage (Oct 29)
- Re: TinyURL Jimmy Alderson (Oct 29)
- Re: TinyURL John Sage (Oct 29)
- Re: TinyURL John Sage (Oct 29)
- RE: TinyURL Steffen Kluge (Oct 30)