CVE-2020-6830Public exploitNetwork attack vector

Bridging token disclosure via window.webkit override

Published May 26, 2020 · Updated Aug 4, 2024

Information disclosure in Mozilla Firefox for iOS before 25 allows remote attackers to obtain a bridging token via a crafted web page. The WKWebView bridge lets page JavaScript replace window.webkit, causing the JS-to-native message handler to return the security token. Visiting an attacker-controlled page is required; the demonstrated consequence is unauthorized access to the token and potential invocation of protected bridge functions.

CVSS severity7.5
High
EPSS probability0.90%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Mozilla Firefox for iOS before 25 allows remote attackers to obtain a bridging token via a crafted web page. The WKWebView bridge lets page JavaScript replace window.webkit, causing the JS-to-native message handler to return the security token. Visiting an attacker-controlled page is required; the demonstrated consequence is unauthorized access to the token and potential invocation of protected bridge functions.

The record

CVE
CVE-2020-6830
Published
May 26, 2020
Updated
Aug 4, 2024
Vendor
Mozilla
Product
Firefox for iOS
Classifications
CWE-200
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 26, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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=unspecified <25

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefox for iOSversion=unspecified <25

Published CVSS scores

7.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NVDAV:N/AC:L/Au:N/C:P/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor

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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