Researcher Awarded $10,000 for Disclosing Critical XSS Vulnerability in Yahoo Mail

A Finland based security researcher named Jouko Pynnönen awarded $10,000 for disclosing critical cross-site scripting (XSS) vulnerability in the webmail version of Yahoo Email service.

An attacker could exploit the vulnerability to compromise the victim accounts, change their email settings and to perform other malicious activities.

The vulnerability resides in the webmail version of the Yahoo service that failed to filter the malicious code in HTML emails.

Pynnönen reported the bug to Yahoo in early December 2018 and the bug was fixed by Yahoo in January and the researcher doesn’t disclose any technical details and he was awarded $10,000 for this bug.

Training Course: Web Hacking and Bug Bounty – Get started in Bug Bounty Program

This is not the first time Pynnönen find’s stored XSS in Yahoo mail, early he discovered a stored XSS in December 2015, which allows an attacker to send a maliciously crafted email with hidden JavaScript code that would get executed once the victim reads the message.

One year later he found another stored XSS vulnerability with the web version of the Yahoo Mail service due to improper sanitization of codes in HTML emails.

DOM-based XSS Vulnerability Affected 685 Million Users of Tinder, Shopify, Western Union, and Imgur

Top 500 Most Important XSS Script Cheat Sheet for Web Application Penetration Testing

Gurubaran

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.

Recent Posts

SPAWNCHIMERA Malware Exploits Ivanti Buffer Overflow Vulnerability by Applying a Critical Fix

In a recent development, the SPAWNCHIMERA malware family has been identified exploiting the buffer overflow…

15 hours ago

Sitevision Auto-Generated Password Vulnerability Lets Hackers Steal Signing Key

A significant vulnerability in Sitevision CMS, versions 10.3.1 and earlier, has been identified, allowing attackers…

15 hours ago

NSA Allegedly Hacked Northwestern Polytechnical University, China Claims

Chinese cybersecurity entities have accused the U.S. National Security Agency (NSA) of orchestrating a cyberattack…

15 hours ago

ACRStealer Malware Abuses Google Docs as C2 to Steal Login Credentials

The ACRStealer malware, an infostealer disguised as illegal software such as cracks and keygens, has…

15 hours ago

Nagios XI Flaw Exposes User Details and Emails to Unauthenticated Attackers”

A security vulnerability in Nagios XI 2024R1.2.2, tracked as CVE-2024-54961, has been disclosed, allowing unauthenticated…

18 hours ago

Critical UniFi Protect Camera Vulnerability Enables Remote Code Execution Attacks

Ubiquiti Networks has issued an urgent security advisory (Bulletin 046) warning of multiple critical vulnerabilities…

18 hours ago