Two years after patch, another IE FTP flaw

Security researchers say that a previously patched IE 6 bug can still be exploited

A flaw in the way Microsoft's Internet Explorer browser processes FTP commands could let attackers steal or erase data from a victim's FTP site.

The bug, which affects users of IE 6 and the unsupported IE 5 browser, gives an attacker a way of hijacking the victim's FTP sessions. But a successful attack would be very hard to pull off and would only work in very precise, targeted attacks, security experts said.

The attacker would need to know the victim's username on the FTP server and the victim would have to already be logged into the server, using IE. Under those conditions, the victim could be sent a malicious FTP link that would then execute commands on the victim's FTP server.

This link could be sent to the browser via an invisible iFrame component, hidden on a malicious Web site, so the victim might not even know the attack was taking place.

"It's something that people could use to steal data, but you'd have to know your target," said Derek Abdine, the principal software engineer with security vendor Rapid7, who disclosed the issue Monday in a security advisory.

"The attack seems viable, but the stars have to be aligned just right for the attack to work," said Craig Schmugar, a researcher with McAfee's Avert Labs, in an e-mail. "An administrator would need to be authenticated already or the server would need to be configured with weak credentials."

Rapid7 notified Microsoft of the issue on Jan. 22 and decided to publish proof-of-concept code that illustrated the flaw after Microsoft had not patched the issue a month later.

The flaw is "almost exactly the same" as another IE FTP flaw that Microsoft patched in August 2006, Abdine said. Microsoft fixed that bug with its MS06-042 patch, issued in August 2006.

The MS06-042 update fixed many IE vulnerabilities, but it ended up embarrassing Microsoft. That's because the security patch had a flaw of its own, a critical security vulnerability that sent Microsoft's security team scrambling to re-issue the update.

The FTP problem does not affect IE 7, Microsoft said Tuesday. The software vendor has not heard of any attacks that take advantage of this vulnerability and has determined that any successful attack would only lead to the unauthorized disclosure of data, the company said in a statement.

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.

Robert McMillan

IDG News Service
Show Comments

Father’s Day Gift Guide

Brand Post

PC World Evaluation Team Review - 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."

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

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?