Authentication bypass via reusable CAPTCHA responses
Published Mar 21, 2023 · Updated Feb 27, 2025
Authentication bypass in Apache Answer before 1.0.6 allows remote attackers to reuse a valid CAPTCHA response and bypass its check. VerifyCaptcha retrieved a cached challenge but did not delete it after successful comparison, leaving the same key and answer valid for replay. No authentication or user interaction is required; the published CNA assessment establishes CAPTCHA-check bypass and limited disclosure, not account takeover.
Summary
What happened
Authentication bypass in Apache Answer before 1.0.6 allows remote attackers to reuse a valid CAPTCHA response and bypass its check. VerifyCaptcha retrieved a cached challenge but did not delete it after successful comparison, leaving the same key and answer valid for replay. No authentication or user interaction is required; the published CNA assessment establishes CAPTCHA-check bypass and limited disclosure, not account takeover.
The record
- CVE
- CVE-2023-1537
- Published
- Mar 21, 2023
- Updated
- Feb 27, 2025
- Vendor
- The Apache Software Foundation
- Product
- Apache Answer
- Classifications
- CWE-294, CAPEC-701
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Mar 21, 2023CVE publishedPublication date reported by the CVE source.
- Feb 27, 2025Record 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 <1.0.6
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
- huntr CAPTCHA replay proof of conceptproof of concept · unverified
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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