CVE-2020-6827Public exploitNetwork attack vector

URI spoofing via intent custom tab

Published Apr 24, 2020 · Updated Aug 4, 2024

URI spoofing in Mozilla Firefox ESR before 68.7 allows remote attackers to display an incorrect address after an intent:// link opens a custom tab. CustomTabsActivity updates the displayed URL on page start even when navigation is aborted, leaving attacker-controlled content under a misleading URI. Exploitation requires a victim to follow a crafted intent:// link in Firefox for Android; desktop operating systems are unaffected and the documented consequence is origin confusion rather than demonstrated code execution.

CVSS severityUnavailable
Unscored
EPSS probability0.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

URI spoofing in Mozilla Firefox ESR before 68.7 allows remote attackers to display an incorrect address after an intent:// link opens a custom tab. CustomTabsActivity updates the displayed URL on page start even when navigation is aborted, leaving attacker-controlled content under a misleading URI. Exploitation requires a victim to follow a crafted intent:// link in Firefox for Android; desktop operating systems are unaffected and the documented consequence is origin confusion rather than demonstrated code execution.

The record

CVE
CVE-2020-6827
Published
Apr 24, 2020
Updated
Aug 4, 2024
Vendor
Mozilla
Product
Firefox ESR
Classifications
T1036
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 24, 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 <68.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefox ESRversion=unspecified <68.7

Published CVSS scores

No CVSS assessment is available in this record.

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.

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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

T1036Masquerading

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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