CVE-2017-20202

Exploitation

Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.

SSVC decision

• ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.50% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 40.4% of scored records. A rank, not a probability.

NVD base score

9.3 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Deferred. NVD last modified this record on 2026-06-17.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2025-10-08 22:04Z11 MO AGO

Last updated

2025-10-14 14:18Z10 MO AGO

Reserved

2025-10-08

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

Critical (CVSS 9.3)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N

Weaknesses

• CWE-506Embedded Malicious CodeClass

Data version

5.1

Document digest

72b407fc2ddf7c9229ca1c8b1ad4c5af02caee3df679f76b304b62227cc68656

• web.archive.orghttps://web.archive.org/web/20170803163618/https://chrispederick.com/blog/web-developer-for-chrome-compromised/vendor-advisorypatch
• ui.visionhttps://ui.vision/blog/chrome-extension-adware/technical-description
• www.proofpoint.comhttps://www.proofpoint.com/us/threat-insight/post/threat-actor-goes-chrome-extension-hijacking-spreetechnical-description
• gist.github.comhttps://gist.github.com/piedpiperRichard/076516da60f45842f1a6e6ae35a9a240/exploit
• chromewebstore.google.comhttps://chromewebstore.google.com/detail/web-developer/bfbameneiokkgbdmiekhjnmfkcnldhhm?pli=1product
• www.vulncheck.comhttps://www.vulncheck.com/advisories/web-developer-for-chrome-malicious-backdoor-supply-chain-compromisethird-party-advisory