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.

Application Security

5/28/2019
03:45 PM
Connect Directly
Twitter
LinkedIn
RSS
E-Mail
50%
50%

Web App Vulnerabilities Flying Under Your Radar

A penetration tester shows how low-severity Web application bugs can have a greater effect than businesses realize.

Organizations could face big problems from seemingly small Web application vulnerabilities. The problem is, many of these bugs fly under the radar because they're not considered severe.

Shandon Lewis, senior Web application penetration tester at Backward Logic, discussed a few of these bugs in his presentation "Vulnerabilities in Web Applications That Are Often Overlooked" at last week's Interop conference. Lewis emphasized the importance of focusing on the bugs attackers are likely to use beyond the zero days that typically make headlines.

In his early days as a red team member, Lewis said he learned "zero days were not the way we get in." The media often focuses on zero-day and stack attacks, he explained, but the most credible threats against a business usually don't come from cybercriminals writing their own bugs. He cited three key ways to "virtually guaranteeing" success when breaking into a target: phishing attacks, physical intrusion (walking into a building and planting a device), and weak passwords.

The latter is easier, more cost-effective, and safer for the adversary, Lewis said. In a typical red team operation, he would first identify the attack surface, locate authentication protocols, password spray, and access the enterprise with discovered credentials. "If you have an authentication portal on the edge and somebody logs in with valid credentials, how do you know they're not the user?" he said, adding he had yet to see a business that could verify this.

There are two components to weak credentials: passwords and usernames. If an attacker doesn't know which format a business uses (firstname.lastname, for example), his first step is to create a list of popular usernames and passwords. Lewis has found the most common passwords are time-based. Because employees are prompted to change their passwords every few months, they tend to choose time-based options. Spring2018 and Spring18 were popular.

"Laziness has gotten a little bit smarter about how it's supposed to be lazy," Lewis joked.

User enumeration, a facilitator vulnerability, enables attackers to guess or confirm valid users on a system. It's typically a Web application vulnerability but can exist on any system that requires people to log in, Rapid7 researchers explain. Attackers hunt for differences in a server's response based on whether the credentials they entered were legitimate. Once they know how the system responds to invalid credentials, they can brute-force usernames and passwords until they unlock the combination that will grant them access to the business.

"Just because it's informational doesn't mean it has zero impact," Lewis said. Informational vulnerabilities, which fall low on the severity scale, provide some information to users that wasn't designed to be released but doesn't have a specific impact. As Venafi researchers put it, informational bugs "can provide attackers with additional information about the operational environment, but rarely result in additional compromise of information or resources."

This wasn't the only bug Lewis discussed in his presentation. Other examples of Web application vulnerabilities included rate limiting, which he said was "a fairly unknown bug" among those who haven't been in the industry a long time. This happens when an app performs a function but fails to realize it has already done it, or performs it repeatedly. This is "a very prevalent problem," he explained, but one that most businesses don't care much about.

Related Content:

Kelly Sheridan is the Staff Editor at Dark Reading, where she focuses on cybersecurity news and analysis. She is a business technology journalist who previously reported for InformationWeek, where she covered Microsoft, and Insurance & Technology, where she covered financial ... View Full Bio
 

Recommended Reading:

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-2021-30477
PUBLISHED: 2021-04-15
An issue was discovered in Zulip Server before 3.4. A bug in the implementation of replies to messages sent by outgoing webhooks to private streams meant that an outgoing webhook bot could be used to send messages to private streams that the user was not intended to be able to send messages to.
CVE-2021-30478
PUBLISHED: 2021-04-15
An issue was discovered in Zulip Server before 3.4. A bug in the implementation of the can_forge_sender permission (previously is_api_super_user) resulted in users with this permission being able to send messages appearing as if sent by a system bot, including to other organizations hosted by the sa...
CVE-2021-30479
PUBLISHED: 2021-04-15
An issue was discovered in Zulip Server before 3.4. A bug in the implementation of the all_public_streams API feature resulted in guest users being able to receive message traffic to public streams that should have been only accessible to members of the organization.
CVE-2021-30487
PUBLISHED: 2021-04-15
In the topic moving API in Zulip Server 3.x before 3.4, organization administrators were able to move messages to streams in other organizations hosted by the same Zulip installation.
CVE-2020-36288
PUBLISHED: 2021-04-15
The issue navigation and search view in Jira Server and Data Center before version 8.5.12, from version 8.6.0 before version 8.13.4, and from version 8.14.0 before version 8.15.1 allows remote attackers to inject arbitrary HTML or JavaScript via a DOM Cross-Site Scripting (XSS) vulnerability caused ...