Obscure hole could expose Hotmail messages

A limited though powerful hole in Hotmail allows hackers to view users' personal e-mail messages.

The hacker group Root Core has published an exploit of a vulnerability in Microsoft Corp.'s free Web-based e-mail service that would allow a user to view the private e-mails of another user. However, attacks must be targeted to a specific user and require some careful guesswork.

Through a spokeswoman, Microsoft said Hotmail engineers have identified the problem and are working to fix the hole. They hope to fix the flaw by the end of the day, she said.

There are two steps involving the hack: first, one must find out the account name (e-mail address) of the Hotmail user; second, you must find out the exact time the message you want to read was sent.

The second step, however, is what makes this exploit difficult. Messages are time-stamped in what appears to be Unix time, or the number of seconds since Jan. 1, 1970, according to Ryan Russell, an analyst at SecurityFocus.com, a business security Web site in San Mateo, California.

"It may help predict what these numbers are. It remains to be seen," he said. If a hacker knows approximately when a message was received, he can set up a program to calculate the seconds and run through messages in a given time frame to find an e-mail.

The published exploit suggests such a solution. "Now [if] typing those message numbers manually is too much work, you could create a small utility to automatically scan [a] given range of messages from specific user name. (You need to build it to work with IE, as you must be logged in Hotmail when you want to view messages...)" Much of the necessary information, however, appears to be missing from the published exploit, Russell said.

"It doesn't explain exactly how to guess the number of the message," Russell said, and at the Root Core Web site, "there has been little discussion on how hard it is."

The immediate concern for Hotmail users isn't grave, he said, since this is a targeted attack. Unlike other exploits, only one user at a time can be affected from a single hacker. He added that Microsoft tends to fix these kinds of holes soon after they're publicized.

However, this exploit points out, "the whole ASP model vulnerability," Russell said. "The good news is Microsoft can fix it in one fell swoop."

It is also difficult for security analysts to test the exploit, he said, since Microsoft could come after them for breaking into other e-mail accounts. "If they really want to know," he said, "They're going to have to put their neck on the line."

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.
Show Comments

Father’s Day Gift Guide

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?