CVE-2017-20202: Web Developer for Chrome v0.4.9 Malicious Backdoor Supply Chain Compromise

Published Oct 8, 2025
·
Updated

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 “repair” 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 include 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. The compromise was reported on by the maintainer of Web Developer for Chrome on August 2, 2017 and remediated in v0.5.0.

Affected Software

1 affected component
Chrome Web Developer=0.4.9

Event History

Oct 8, 2025
CVE Published
via MITRE·10:04 PM
Data Sourced
via MITRE·10:04 PM
DescriptionWeakness
Data Sourced
via NVD·10:15 PM
DescriptionSeverityWeakness
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Frequently Asked Questions

1

What is the severity of CVE-2017-20202?

CVE-2017-20202 is considered a high severity vulnerability due to its malicious nature and affected users.

2

How can I remove the malicious code associated with CVE-2017-20202?

To remove the malicious code from CVE-2017-20202, uninstall the compromised Web Developer extension from your Chrome browser.

3

What software versions are affected by CVE-2017-20202?

CVE-2017-20202 specifically affects Web Developer for Chrome version 0.4.9.

4

What types of attacks are enabled by CVE-2017-20202?

CVE-2017-20202 enables extensive ad substitution, malvertising, and fake ‘repair’ alerts that can redirect users.

5

How was the vulnerability CVE-2017-20202 utilized by attackers?

Attackers utilized CVE-2017-20202 by generating domains through a DGA and fetching remote scripts to execute malicious activities.

Contact

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