LinkedIn Security Flaws Revealed by an Indian Security Expert

Business-related social networking site LinkedIn has security flaws that makes users’ accounts vulnerable to attack by hackers who could break in without ever needing passwords, according to a security researcher who discovered the problem.

Rishi Narang, an independent Internet security researcher based near New Delhi, identified the security flaw. He told that the problem is related to the way LinkedIn manages a commonly used type of data file cookie.

After a user enters the proper username and password to access an account, LinkedIn’s system creates a cookie “LEO_AUTH_TOKEN” on the user’s computer that serves as a key to gain access to the account. LinkedIn cookie does not expire for a full year from the date it is created. The long life of the LinkedIn cookie means that anybody who gets hold of that file can load it on to a PC and easily gain access to the original user’s account for as much as a year.

[advt]The company issued a statement saying that it already takes steps to secure the accounts of its customers. The company said that it currently supports SSL( secure sockets layer) technology for encrypting certain “sensitive” data, including account logins. LinkedIn said in its statement that it is preparing to offer “opt-in” SSL support for other parts of the site, an option that would cover encryption of those cookies. The company said it expected that to be available “in the coming months.”

But those access token cookies are not yet scrambled with SSL. That makes it possible for hackers to steal the cookies using widely available tools for sniffing Internet traffic, Narang said. But LinkedIn officials declined to respond to Narang’s critique of the company’s use of a cookie with a one-year expiration.

Narang said that problem is particularly acute because LinkedIn’s users are not aware of the problem and have no idea that they should be protecting those cookies. He said he found four cookies with valid LinkedIn access tokens had been uploaded to a LinkedIn developer forum by users who were posting questions about their use. He said he downloaded those cookies and was able to access the accounts of the four LinkedIn subscribers.[source]