Time Slots Booking CalendarApplication · Phpjabbers

CVE-2023-33562

CRITICAL · 9.8 CVSS v3.1 Published 2023-08-01
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
User enumeration is found in in PHP Jabbers Time Slots Booking Calendar v3.3. This issue occurs during password recovery, where a difference in messages could allow an attacker to determine if the user is valid or not, enabling a brute force attack with valid users.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

User enumeration vulnerability in PHP Jabbers Time Slots Booking Calendar v3.3 password recovery. The application returns different error messages for existing versus non-existing users, allowing attackers to confirm valid usernames through the password reset function. This information enables targeted brute force attacks against confirmed accounts.

MitigationReplace password recovery error messages with generic responses that don't reveal user existence, and implement rate limiting or account lockout policies on authentication endpoints to prevent automated enumeration and brute force attempts.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Time Slots Booking CalendarApplication
Affected:= 3.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the installed version of PHP Jabbers Time Slots Booking Calendar
    Check your web application files or admin panel for the version number. Look in the application configuration files, footer, or admin dashboard typically found under /admin/ or in a setup/includes directory.
    Affected if The installed version is 3.3 exactly, as this is the only affected version for this CVE.
  2. Locate the password recovery functionality
    Navigate to the password reset or forgot password feature on your PHP Jabbers Time Slots Booking Calendar installation. This is typically found on the login page or at a URL path containing 'password', 'reset', 'forgot', or 'recovery'.
    Affected if The password recovery functionality exists and is accessible on the affected version.
  3. Test error response for a non-existing username
    Submit a password recovery request using a username or email address that does not exist in the system. Note the exact error message or response returned by the application.
    Affected if The application returns a specific error message indicating the user does not exist.
  4. Test error response for an existing username
    Submit a password recovery request using a username or email address that is confirmed to exist in the system (such as your own admin account). Note the exact error message or response returned by the application.
    Affected if The application returns a different error message than the one for non-existing users, such as sending an actual password reset email or showing a success message.
  5. Compare the two error message responses
    Compare the exact wording and behavior of the responses from steps 3 and 4. Document whether the application reveals user existence through different error messages or response behaviors.
    Affected if The responses differ between existing and non-existing users, confirming user enumeration is possible.

Your environment is affected if you are running PHP Jabbers Time Slots Booking Calendar version 3.3 and the password recovery function returns different error messages or behaviors for existing versus non-existing user accounts, allowing an attacker to enumerate valid usernames.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Replace password recovery error messages with generic responses that don't reveal user existence, and implement rate limiting or account lockout policies on authentication endpoints to prevent automated enumeration and brute force attempts.

Fix this in Time Slots Booking Calendar Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing3.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,490
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2023-33562 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data