Phishing via incorrect IDN URL parsing
Published Dec 8, 2021 · Updated Aug 4, 2024
URL parsing in Mozilla Firefox before 94 allows remote attackers to induce user confusion and phishing via crafted internationalized domains. The IDN parser strips high bits from URL characters before converting them to display form, causing a hostname to be interpreted differently from the intended domain. Exploitation requires a user to load or inspect an attacker-controlled URL; the documented consequence is spoofing or phishing rather than code execution.
Summary
What happened
URL parsing in Mozilla Firefox before 94 allows remote attackers to induce user confusion and phishing via crafted internationalized domains. The IDN parser strips high bits from URL characters before converting them to display form, causing a hostname to be interpreted differently from the intended domain. Exploitation requires a user to load or inspect an attacker-controlled URL; the documented consequence is spoofing or phishing rather than code execution.
The record
- CVE
- CVE-2021-43533
- Published
- Dec 8, 2021
- Updated
- Aug 4, 2024
- Vendor
- Mozilla
- Product
- Firefox
- Classifications
- T1566
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 8, 2021CVE publishedPublication date reported by the CVE source.
- 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?
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- Affected versionversion=unspecified <94
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.
Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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