A new series of critical eBay vulnerabilities still menaces 145M users

Pierluigi Paganini May 24, 2014

Security experts have discovered three new critical eBay vulnerabilities, the privacy and data of more than 145 million users is still at risk.

Just a few days after the disclosure of a major data breach at eBay, in the Internet is circulating the news of three new critical eBay vulnerabilities in the company website.

eBay admitted that the cyber attack has impacted nearly 145 million registered users worldwide, company database was violated by the hackers and the company immediately requested its customers to change their passwords.

The new three critical eBay vulnerabilities, which have been disclosed by three security experts, could allow an attacker to compromise any user account, even if he has already reset the password after the last announcement.

I decided to respond to the appeal of colleagues at TheHackerNews sharing the info the presented in an interesting post.

1- Persistent Cross-Site Scripting (XSS)

The first vulnerability is a Persistent Cross-Site Scripting (XSS) on eBay Website, the flaw was reported by the German security researcher Michael E. to The Hacker News , he discovered a bug on the auction pages that allowed him to inject arbitrary HTML and Javascript code into the eBay website.

Each time a user visits a malicious auction page created by the attacker, the XSS vulnerability will allow to the attackers the execution of unauthorized Javascript code victim’ browser with a payload to steal its account cookies. With this technique a hacker could easily hijack the user’s account, as demonstrated by Michael in the following proof-of-concept auction page:

http://www.ebay.de/itm/script-script-alert-1-script-x-onfocus-alert-1-autofocus-onl-/281257333177

2 – Uploaded shell on eBay server

One of the worst scenarios for a security expert is the presence of a shell on its system, this is the theme of the second vulnerability. The security researcher Jordan Jones discovered a critical vulnerability in the eBay website for its employees could allow an attacker to upload a backdoor shell, more details are available on his blog post.

The expert has already reported the vulnerability to the eBay Research Labs page (labs.ebay.com), the following image is a proof-of-concept screenshot for successfully upload of a ‘shell.php’ file (as shown) on the server to control it.

The backdoor, rendered helpless, was deployed at the following address.

https://dsl.ebay.com/wp-includes/Text/Diff/Engine/shell.php“

3 – Account Hijacking vulnerability

The Egyptian security researcher ‘Yasser H. Ali’ reported to The Hacker News a critical vulnerability on the eBay website that could be exploited to hijack millions of user accounts in bulk. The flaw is still un-patched but experts at THN avoided to provide details since eBay security team will work on it.

This flaw could have a serious impact and Yasser demonstrated it privately to the team of experts at THN.

Experts at THN has also discovered a further eBay vulnerability:

COOKIE RE-USE VULNERABILITY (UNPATCHED) – eBay allows the reuse of same login cookies even if the user has logged out or reset its password.

“Which means by using Michael’s persistent XSS vulnerability, one can steal eBay users’ account cookies in order to get an unauthorized access to the users’ respective accounts, without knowing their previous or updated passwords.” states THN.

Let’s wait for resolution of eBay vulnerabilities, I sincerely hope that their security team will fix them asap to avoid further and dangerous problems to the users and to the image of the company itself.

Pierluigi Paganini

(Security Affairs – eBay vulnerabilities, hacking)

data breach EBay eBay vulnerabilities Hacking password privacy The Hacker News

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