Friday, May 24, 2024

Attackers can Steal Sensitive Data by Abusing CSS – CSS Exfil Vulnerability

CSS is a stylesheet language which provides a presentation for documents, all our modern websites heavily depend on the CSS. A new CSS vulnerability dubbed CSS Exfil can be used by attackers to steal data from the webpages using CSS.

With the vulnerability, attackers can steal sensitive data’s including usernames, passwords, and sensitive data such as date of birth, social security numbers, and credit card numbers. Also, this method can de-anonymize Tor users.

Gualtieri says “By crafting targeted CSS selectors and injecting them into a web page, an attacker can trick the page into sending pieces of data to a remote server (e.g. usernames, passwords, and sensitive data such as date of birth, social security numbers, and credit card numbers).”

Also Read New Attack Called “XSSJacking” Discovered That Combined of Clickjacking, Pastejacking and Self-XSS Attacks

Attackers can inject CSS, take full control over the look and feel of the website and even steal the data. Also, the exfiltration is easy as they use only CSS.

Attack Methods

Attackers can launch various attack scenarios to leverage the CSS Exfil vulnerability

  • Reflected or stored code injection flaws.
  • Malicious third-party components.
  • Hijacked browser extensions.
  • DOM elements that added accidentally.

Researchers published PoC explaining CSS Exfil attack to leak page data, stealing password stealing username and date of birth.

A test page was published by the researcher to check your browser against the vulnerability and the test page attempts to load four remote images using CSS selectors which parse a hidden text field. If it is able to load any of those four images your browser is vulnerable to the CSS Exfil attack.

Also, another researcher detailed stealing CSRF token in 10 seconds with CSS injection, once the attacker has stolen the victim CSRF token, he can complete CSRF attack against the user.

Defense Suggested – CSS Exfil

Researchers suggested website owners to use Content Security Policy to limit the ability of an attacker to use the remote URL’s. Fixing code injection flaws and using a Web Application Firewall would help.

The best defense for the users is to disable the execution of that CSS in the browser, researchers submitted plugins for Chrome and Firefox to defend against the CSS Exfil attacks.

Website

Latest articles

Hackers Weaponizing Microsoft Access Documents To Execute Malicious Program

In multiple aggressive phishing attempts, the financially motivated organization UAC-0006 heavily targeted Ukraine, utilizing...

Microsoft Warns Of Storm-0539’s Aggressive Gift Card Theft

Gift cards are attractive to hackers since they provide quick monetization for stolen data...

Kinsing Malware Attacking Apache Tomcat Server With Vulnerabilities

The scalability and flexibility of cloud platforms recently boosted the emerging trend of cryptomining...

NSA Releases Guidance On Zero Trust Maturity To Secure Application From Attackers

Zero Trust Maturity measures the extent to which an organization has adopted and implemented...

Chinese Hackers Stay Hidden On Military And Government Networks For Six Years

Hackers target military and government networks for varied reasons, primarily related to spying, which...

DNSBomb : A New DoS Attack That Exploits DNS Queries

A new practical and powerful Denial of service attack has been discovered that exploits...

Malicious PyPI & NPM Packages Attacking MacOS Users

Cybersecurity researchers have identified a series of malicious software packages targeting MacOS users.These...
Guru baran
Guru baranhttps://gbhackers.com
Gurubaran is a co-founder of Cyber Security News and GBHackers On Security. He has 10+ years of experience as a Security Consultant, Editor, and Analyst in cybersecurity, technology, and communications.

Free Webinar

Live API Attack Simulation

94% of organizations experience security problems in production APIs, and one in five suffers a data breach. As a result, cyber-attacks on APIs increased from 35% in 2022 to 46% in 2023, and this trend continues to rise.
Key takeaways include:

  • An exploit of OWASP API Top 10 vulnerability
  • A brute force ATO (Account Takeover) attack on API
  • A DDoS attack on an API
  • Positive security model automation to prevent API attacks

Related Articles