Unauthenticated CAPTCHA bypass via exposed weak hash
Published Nov 29, 2022 · Updated Apr 8, 2026
CAPTCHA bypass in CodePeople Appointment Hour Booking – Booking Calendar 1.3.72 and earlier allows remote attackers to evade human verification. The booking form weakly hashes its CAPTCHA secret and also exposes that secret in a client cookie, making the expected answer guessable. No authentication or user interaction is required; the confirmed consequence is bypass of the form's anti-automation check, with no published evidence of data modification or service interruption.
Summary
What happened
CAPTCHA bypass in CodePeople Appointment Hour Booking – Booking Calendar 1.3.72 and earlier allows remote attackers to evade human verification. The booking form weakly hashes its CAPTCHA secret and also exposes that secret in a client cookie, making the expected answer guessable. No authentication or user interaction is required; the confirmed consequence is bypass of the form's anti-automation check, with no published evidence of data modification or service interruption.
The record
- CVE
- CVE-2022-4036
- Published
- Nov 29, 2022
- Updated
- Apr 8, 2026
- Vendor
- CodePeople
- Product
- Appointment Hour Booking – Booking Calendar
- Classifications
- CWE-804, CWE-326, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Nov 29, 2022CVE publishedPublication date reported by the CVE source.
- Apr 8, 2026Record 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=0 <=1.3.72
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
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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