Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Vulnerabilities / Threats

LinkedIn Faces Cookie Vulnerabilities

The social networking site is set to reduce the length of time before cookies expire and add HTTPS across its site.

How Firesheep Can Hijack Web Sessions
(click image for larger view)
Slideshow: How Firesheep Can Hijack WebSessions
LinkedIn users' accounts are vulnerable to hijacking, due to the manner in which the social networking site handles its website cookies.

That security warning comes from Rishi Narang, a security consultant at website scanning firm Hackers Locked, who published an analysis of the vulnerability on Saturday.

LinkedIn is much in the news lately, owing to its initial public offering on Thursday, which by the close of the day resulted in the company being valued at $8.9 billion. But is the company paying enough attention to the security of its users?

LinkedIn, like many websites, uses cookies to store, on a PC, session information relating to anyone who uses that PC to access LinkedIn. Such cookies make it easy for users to later access LinkedIn without having to enter a username or password. But according to Narang, LinkedIn needs to handle its cookies better.

All told, there are two cookie-related vulnerabilities, he said. The first stems from LinkedIn SSL cookies not using a secure flag, which means that session credentials are sent in plaintext. As a result, they're susceptible to a man-in-the-middle attack, which could intercept these credentials. Such an attack could be launched from a third-party website by remotely redirecting a user to the HTTPS log-in page for LinkedIn, and watching the relevant credentials being passed back and forth.

A fix, however, is relatively simple: LinkedIn should use the secure flag on any cookies that are used with an HTTPS page, such as the log-in page, said Narang. "If the secure flag is set on a cookie, then browsers will not submit the cookie in any requests that use an unencrypted HTTP connection, thereby preventing the cookie from being trivially intercepted by an attacker monitoring network traffic," he said. "If the secure flag is not set, then the cookie will be transmitted in clear text if the user visits any HTTP URLs within the cookie's scope." Another security improvement would be for LinkedIn to restrict credentials to a specific IP address, as Gmail does. That way, if an attacker stole a credential and attempted to use it from another PC, it wouldn't work.

The second vulnerability, he said, is due to LinkedIn setting its cookies to not expire for one year--an eternity, in website time--and not canceling cookies if a user logs out. "As a result of valid cookies, an attacker can sniff the cookies from [a] clear-text session," as detailed with the prior vulnerability, said Narang. With cookies in hand, an attacker could then authenticate as the other user. "He can then compromise and modify the information available at the user profile page," he said.

Accordingly, this vulnerability rates largely as a nuisance, since LinkedIn doesn't store people's financial information. On the other hand, in the wrong hands, a LinkedIn account hijacking or defacement could be quite embarrassing. Furthermore, intercepting people's LinkedIn credentials is relatively easy--if they're using an unsecured, public Wi-Fi hotspot--by using a tool such as Firesheep.

LinkedIn said it's working on related improvements, but in the short term, recommended users avoid unsecured networks. "Whether you are on LinkedIn or any other site, it's always a good idea to choose trusted and encrypted Wi-Fi networks or VPNs whenever possible," said a LinkedIn spokesperson via email. "If one isn't available, we already support SSL for logins and other sensitive Web pages."

Going forward, he said, LinkedIn plans to support SSL--as in, HTTPS pages--across the entire site. As with Facebook, users will need to opt in. Furthermore, "we are going to reduce the lifespan of the cookies in question from 12 months to 90 days," said the spokesperson.

"LinkedIn takes the privacy and security of our members seriously, while also looking to deliver a great site experience, and we believe these two changes will allow us to strike that balance," he said.

In this new Tech Center report, we profile five database breaches--and extract the lessons to be learned from each. Plus: A rundown of six technologies to reduce your risk. Download it here (registration required).

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
News
Inside the Ransomware Campaigns Targeting Exchange Servers
Kelly Sheridan, Staff Editor, Dark Reading,  4/2/2021
Commentary
Beyond MITRE ATT&CK: The Case for a New Cyber Kill Chain
Rik Turner, Principal Analyst, Infrastructure Solutions, Omdia,  3/30/2021
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
2021 Top Enterprise IT Trends
We've identified the key trends that are poised to impact the IT landscape in 2021. Find out why they're important and how they will affect you today!
Flash Poll
How Enterprises are Developing Secure Applications
How Enterprises are Developing Secure Applications
Recent breaches of third-party apps are driving many organizations to think harder about the security of their off-the-shelf software as they continue to move left in secure software development practices.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2021-26030
PUBLISHED: 2021-04-14
An issue was discovered in Joomla! 3.0.0 through 3.9.25. Inadequate escaping allowed XSS attacks using the logo parameter of the default templates on error page
CVE-2021-26031
PUBLISHED: 2021-04-14
An issue was discovered in Joomla! 3.0.0 through 3.9.25. Inadequate filters on module layout settings could lead to an LFI.
CVE-2021-27710
PUBLISHED: 2021-04-14
Command Injection in TOTOLINK X5000R router with firmware v9.1.0u.6118_B20201102, and TOTOLINK A720R router with firmware v4.1.5cu.470_B20200911 allows remote attackers to execute arbitrary OS commands by sending a modified HTTP request. This occurs because the function executes glibc's system funct...
CVE-2021-28484
PUBLISHED: 2021-04-14
An issue was discovered in the /api/connector endpoint handler in Yubico yubihsm-connector before 3.0.1 (in YubiHSM SDK before 2021.04). The handler did not validate the length of the request, which can lead to a state where yubihsm-connector becomes stuck in a loop waiting for the YubiHSM to send i...
CVE-2021-29654
PUBLISHED: 2021-04-14
AjaxSearchPro before 4.20.8 allows Deserialization of Untrusted Data (in the import database feature of the administration panel), leading to Remote Code execution.