CVE-2017-20199Public exploitNetwork attack vector

Password disclosure via unrestricted vault queries

Published Aug 15, 2025 · Updated Aug 27, 2025

Credential disclosure in Buttercup Browser Extension 0.14.0 through 0.14.2 allows remote attackers to read passwords via a crafted web page. The Vault Handler answers password lookup requests from arbitrary page scripts instead of restricting them to an authorized origin or approved action. An unlocked vault and a visit to attacker-controlled content are required; exploitation discloses matching saved passwords without modifying the vault.

CVSS severity3.1
Low
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Credential disclosure in Buttercup Browser Extension 0.14.0 through 0.14.2 allows remote attackers to read passwords via a crafted web page. The Vault Handler answers password lookup requests from arbitrary page scripts instead of restricting them to an authorized origin or approved action. An unlocked vault and a visit to attacker-controlled content are required; exploitation discloses matching saved passwords without modifying the vault.

The record

CVE
CVE-2017-20199
Published
Aug 15, 2025
Updated
Aug 27, 2025
Vendor
Buttercup
Product
Buttercup Browser Extension
Classifications
CWE-284, CWE-266, T1555.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 15, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.14.0
  2. Affected versionversion=0.14.1
  3. Affected versionversion=0.14.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Buttercup · Buttercup Browser Extensionversion=0.14.0; version=0.14.1; version=0.14.2

Published CVSS scores

2.6VulDBAV:N/AC:H/Au:N/C:P/I:N/A:N
2.3VulDBCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P
3.1VulDBCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-284Improper Access Control
CWE-266Incorrect Privilege Assignment
T1555.003Credentials from Web Browsers

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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