Risk
9/1/2009
03:49 PM
Connect Directly
Google+
Twitter
RSS
E-Mail
50%
50%

Flaw In Sears Website Left Database Open To Attack

Business-logic flaw in Sears.com Web application could have let hackers brute-force attack the retailer's gift card database

A newly discovered vulnerability on Sears.com could have allowed attackers to raid the retail giant's gift card database.

Alex Firmani, owner of Merge Design and a researcher, this week revealed a major security hole on Sears.com that could allow an attacker to easily steal valid gift cards -- a heist he estimates could be worth millions of dollars. Firmani says he alerted Sears about the flaw, and that Sears has since "plugged" the hole by removing the feature that let customers verify and check their gift-card balances.

The vulnerability was a business logic flaw in a Web application that handles gift card account inquiries; Firmani was able to stage a brute-force attack that could grab all valid, active Sears and Kmart gift cards from the company's database.

Firmani says the site wasn't auditing verification requests, which allowed him to verify gift card and PIN combinations using a homegrown PHP script that automatically submitted the requests. "I wrote a PHP script to hammer their verification server. It happily replied with thousands of verification responses per minute," he says.

The Sears application relied on client-side cookies to halt brute-force verification attempts, which Firmani says wasn't effective. "They should know where the verification requests come from, log them all, and be able to disable the verifications when they have a malicious attack," he says. "It doesn't appear to me that they had any server-side control over how many verifications were done."

Jeremiah Grossman, CTO of WhiteHat Security, says this type of flaw is probably fairly common on retailer Websites. And unlike a cross-site scripting or SQL injection bug, this business logic flaw is different: "It basically lets an attacker defraud Sears.com directly," Grossman says.

Firmani's discovery came on the heels of reports of multiple cross-site scripting (XSS) vulnerabilities on Sears' Web pages that were abused by an attacker to deface the Website.

"I thought this was notable with Sears being a Fortune 50 company," he says. "I have not tested many other large retailers, but I would hope most of them take better care than this. For smaller sites that write their own gift-card verification code, I'd expect just as many are vulnerable."

Firmani, who says he discloses Website flaws to site owners in order to highlight common Web application security issues, suggests that Sears require a valid user account login before allowing a verification request to be sent. "You could then record the number of verification requests and lock out any offending accounts automatically and without relying on client-side cookie," he wrote in his disclosure paper. "Recording requests server-side would be a more reliable way of handling repeat request offenders."

Another option is recording to a server-side database IP addresses of users verifying their gift cards, he said, as well as using a "number-used once" scheme in the verification form or logging all verification requests and using a script to shut down the response server if more than a specifically designated number of requests arrive per minute, he said.

"Security these days is less about what version of Apache you're running and more about custom-written Web applications. With Web apps given unfettered database access, it becomes a simple matter of exploiting less-than-solid Web application programming," Firmani says. "Finding holes in home-brewed Web app code is much easier than exploiting a root-escalation bug on a Linux server, but both often have similar database access."

Have a comment on this story? Please click "Discuss" below. If you'd like to contact Dark Reading's editors directly, send us a message. Kelly Jackson Higgins is Executive Editor at DarkReading.com. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise ... View Full Bio

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Register for Dark Reading Newsletters
White Papers
Video
Cartoon Contest
Current Issue
Security Operations and IT Operations: Finding the Path to Collaboration
A wide gulf has emerged between SOC and NOC teams that's keeping both of them from assuring the confidentiality, integrity, and availability of IT systems. Here's how experts think it should be bridged.
Flash Poll
New Best Practices for Secure App Development
New Best Practices for Secure App Development
The transition from DevOps to SecDevOps is combining with the move toward cloud computing to create new challenges - and new opportunities - for the information security team. Download this report, to learn about the new best practices for secure application development.
Slideshows
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2017-0290
Published: 2017-05-09
NScript in mpengine in Microsoft Malware Protection Engine with Engine Version before 1.1.13704.0, as used in Windows Defender and other products, allows remote attackers to execute arbitrary code or cause a denial of service (type confusion and application crash) via crafted JavaScript code within ...

CVE-2016-10369
Published: 2017-05-08
unixsocket.c in lxterminal through 0.3.0 insecurely uses /tmp for a socket file, allowing a local user to cause a denial of service (preventing terminal launch), or possibly have other impact (bypassing terminal access control).

CVE-2016-8202
Published: 2017-05-08
A privilege escalation vulnerability in Brocade Fibre Channel SAN products running Brocade Fabric OS (FOS) releases earlier than v7.4.1d and v8.0.1b could allow an authenticated attacker to elevate the privileges of user accounts accessing the system via command line interface. With affected version...

CVE-2016-8209
Published: 2017-05-08
Improper checks for unusual or exceptional conditions in Brocade NetIron 05.8.00 and later releases up to and including 06.1.00, when the Management Module is continuously scanned on port 22, may allow attackers to cause a denial of service (crash and reload) of the management module.

CVE-2017-0890
Published: 2017-05-08
Nextcloud Server before 11.0.3 is vulnerable to an inadequate escaping leading to a XSS vulnerability in the search module. To be exploitable a user has to write or paste malicious content into the search dialogue.

Dark Reading Radio
Archived Dark Reading Radio
In past years, security researchers have discovered ways to hack cars, medical devices, automated teller machines, and many other targets. Dark Reading Executive Editor Kelly Jackson Higgins hosts researcher Samy Kamkar and Levi Gundert, vice president of threat intelligence at Recorded Future, to discuss some of 2016's most unusual and creative hacks by white hats, and what these new vulnerabilities might mean for the coming year.