Finally, the English version of “JavaScript prototype pollution: practice of finding and exploitation” article is prepared. Using the techniques Nikita Stupin discovered CVE-2020–28460 in multi-ini parser and a vulnerability in the merge-deep package. With the first one, everything went smoothly, but with the second one, a funny situation came out: after sending the report, the maintainer did not get in touch for a long time, and as a result, GitHub Security Lab found the same vulnerability, managed to reach the maintainer earlier and registered it (GHSL-2020–160). All details related to these vulnerabilities, discovery and exploitation techniques, and recommendations on how to protect your applications are collected in the article.
Denis Makrushin

Denis Makrushin
Denis is chief technology officer of cybersecurity product line at telecommunications company. He is responsible for product development, defining technology strategy and driving future technical innovation.
If you regularly monitor bug bounty reports, you’ve seen “JavaScript prototype pollution” titles. Nikita Stupin decided to dig deeper into the category of vulnerabilities, impacting JavaScript applications, and prepared the practical guide of its discovery and exploitation. Soon we will also prepare an English version of the paper, but currently, you have to manage by yourself to translate it.
For everyone who wants to start new year productively and begin the journey in #AppSec, I'll introduce “Web App Bug Hunting: Fundamentals and Learning Path” workshop on #SINCON. Thanks to @dariaski and @Emil0xA for the opportunity. Workshop details: https://t.co/sEpB73RvTh https://t.co/nIoKt2JmCv
— Denis Makrushin (@makrushind) January 2, 2021
For everyone who wants to start the new year productively and begin the journey in application security, I will introduce “Web Applications Bug Hunting: Fundamentals and Learning Path” workshop on SINCON.
Once bug hunting becomes a race of known misconfigurations and CVE detection, automation is required:
- monitor daily #BugBountyTips and CVEs;
- filter results with trendy potential;
- get alerts on time (13:37 UTC +0).
“Bug Hunting Hub” is a Telegram channel with my notes and bot notifications.