CVE-2017-20202
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-10-08

Last updated on: 2025-10-14

Assigner: VulnCheck

Description
Web Developer for Chrome v0.4.9 contained malicious code that generated a domain via a DGA and fetched a remote script. The fetched script conditionally loaded follow-on modules that performed extensive ad substitution and malvertising, displayed fake β€œrepair” alerts that redirected users to affiliate programs, and attempted to harvest credentials when users logged in. Injected components enumerate common banner sizes for substitution, replace third-party ad calls, and redirect victim traffic to affiliate landing pages. Potential impacts includeΒ user-level code execution in the browser context, large-scale ad fraud and traffic hijacking, credential theft, and exposure to additional payloads delivered by the actor.Β The compromise was reported on by the maintainer of Web Developer for Chrome on August 2, 2017 and remediated in v0.5.0.
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Meta Information
Published
2025-10-08
Last Modified
2025-10-14
Generated
2026-05-07
AI Q&A
2025-10-09
EPSS Evaluated
2026-05-05
NVD
Affected Vendors & Products
Showing 2 associated CPEs
Vendor Product Version / Range
copyfish copyfish 2.8.5
chrome web_developer 0.4.9
Helpful Resources
Exploitability
CWE
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KEV
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CWE ID Description
CWE-506 The product contains code that appears to be malicious in nature.
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?

The vulnerability in Web Developer for Chrome v0.4.9 involved malicious code that generated domains via a Domain Generation Algorithm (DGA) to fetch remote scripts. These scripts conditionally loaded additional modules that performed extensive ad substitution and malvertising, displayed fake repair alerts redirecting users to affiliate programs, and attempted to steal user credentials during login. The injected components replaced third-party ads with fraudulent ones and redirected victim traffic to affiliate landing pages. This allowed the attacker to execute code in the browser context and carry out large-scale ad fraud and credential theft.


How can this vulnerability impact me? :

This vulnerability can impact users by enabling user-level code execution within the browser, leading to large-scale ad fraud and traffic hijacking. It can also result in credential theft when users log in, exposure to additional malicious payloads, and redirection to fraudulent affiliate landing pages. Overall, it compromises user security and privacy.


What immediate steps should I take to mitigate this vulnerability?

Update the Web Developer for Chrome extension to version 0.5.0 or later, as the vulnerability was remediated in that version. Additionally, remove or disable the compromised version 0.4.9 to prevent malicious code execution and associated impacts such as ad fraud, credential theft, and traffic hijacking.


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