Credential phishing via omitted popup identity prefix
Published Mar 31, 2021 · Updated Aug 3, 2024
UI spoofing in Mozilla Firefox before 87, Firefox ESR before 78.9, and Thunderbird before 78.9 allows attackers to spoof websites. In getWindowTitleForBrowser, a stale Services.uriFixup.createExposableURI call throws an error that a catch block silently ignores, skipping the page URL or extension prefix. Exploitation requires a malicious extension to open an address-bar-free popup and user interaction to enter credentials; the flaw does not itself disclose them.
Summary
What happened
UI spoofing in Mozilla Firefox before 87, Firefox ESR before 78.9, and Thunderbird before 78.9 allows attackers to spoof websites. In getWindowTitleForBrowser, a stale Services.uriFixup.createExposableURI call throws an error that a catch block silently ignores, skipping the page URL or extension prefix. Exploitation requires a malicious extension to open an address-bar-free popup and user interaction to enter credentials; the flaw does not itself disclose them.
The record
- CVE
- CVE-2021-23984
- Published
- Mar 31, 2021
- Updated
- Aug 3, 2024
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- CWE-290, T1056.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 31, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 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.
- Affected versionversion=unspecified <87
What conditions does exploitation require?
What is affected?
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.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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