LinkedIn cookie vulnerable, claims researcher

Fresh from an IPO in which its bankers sent millions to pre-float insiders by low-balling its price, LinkedIn has been accused of slack security by Indian security Rishi Narang. Narang, who published his analysis of LinkedIn cookie handling here, identified two cookie handling problems: an SSL cookie is used without having its …

[Anonymous Coward]

Grrrr.

Can we process the bastards under the CAN-SPAM act? I'm still getting annoying invitations and reminders from people I barely know (or don't know at all) and there is no apparent way to opt out.

[Elmer Phud]

Filter time

I've knocked up a filter that dumps anything with 'LinkedIn' in the message.

The messages were either (apparently) from people I know but have no desire to become part of thier spam list or people I don't know at all.

I don't get to see the messages anymore.

[Simon Barnes]

And, we are going to reduce the lifespan of the cookies in question from 12 months to 90 days.

...which won't make any difference to the vulnerability described :(

[Woodgar]

Re: 12 months to 90 days

My thoughts exactly.

It's as though they didn't have any understanding of what the problem was in the first place.

[mikeoneill]

LinkedIn button

LinkedIn sets their login cookie to be persistant, and also does not set the secure flag, so that it will be sent back to them whenever a user visits any page that has a LinkedIn profile or share button on it. This is similar to how the Facebook "like" button works, although LinkedIn seem to rely on getting the URL of the visited page through the Referer: header, while Facebook has it encoded in the query string (also). Normally login cookies expire at the end of a session, or after a short period, as they are only normally needed to maintain state during a logged in session.

This technique lets social network sites build up a record of the sites you visit and associate it with your login profile, so you can be targeted with ads etc.