User enumeration via divergent authentication failures
Published May 13, 2021 · Updated Aug 3, 2024
Information disclosure in Symfony 2.8.0 through 3.4.47, 4.0.0 through 4.4.22, and 5.0.0 through 5.2.7 allows remote attackers to enumerate users. GuardAuthenticationListener and UserAuthenticationProvider expose different exception messages and authentication timing for existing and nonexistent accounts. No authentication or user interaction is required; the result is limited to learning whether supplied account names exist.
Summary
What happened
Information disclosure in Symfony 2.8.0 through 3.4.47, 4.0.0 through 4.4.22, and 5.0.0 through 5.2.7 allows remote attackers to enumerate users. GuardAuthenticationListener and UserAuthenticationProvider expose different exception messages and authentication timing for existing and nonexistent accounts. No authentication or user interaction is required; the result is limited to learning whether supplied account names exist.
The record
- CVE
- CVE-2021-21424
- Published
- May 13, 2021
- Updated
- Aug 3, 2024
- Vendor
- Symfony
- Product
- Symfony
- Classifications
- CWE-200, CWE-203, T1087
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 13, 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=>= 2.8.0, < 3.4.48
- Affected versionversion=>= 4.0.0, < 4.4.23
- Affected versionversion=>= 5.0.0, < 5.2.8
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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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