CVE-2023-36135
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 · uneditedUser enumeration is found in in PHPJabbers Class Scheduling System v1.0. 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 confidenceUser enumeration vulnerability in PHPJabbers Class Scheduling System v1.0 password recovery function. The application returns different error messages for valid versus invalid usernames, allowing attackers to identify valid user accounts and subsequently launch targeted brute force attacks.
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= 1.0CVSS 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
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
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 checksWork through these to decide whether this CVE applies to you.
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Confirm PHPJabbers Class Scheduling System installationIdentify if PHPJabbers Class Scheduling System v1.0 is deployed in your environment by checking the application or source files for version identificationAffected if The application is running PHPJabbers Class Scheduling System version 1.0
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Locate the password recovery endpointNavigate to the password recovery or forgot password page in the web application and identify the form submission URLAffected if The password recovery functionality is accessible and enabled
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Test error message response for invalid usernameSubmit a clearly non-existent username (e.g., 'nonexistentuser123xyz') into the password recovery form and record the exact error message returned by the applicationAffected if An error message is displayed for the invalid username
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Test error message response for valid usernameSubmit a known valid username (such as 'admin' or another default account) into the password recovery form and record the exact error message returnedAffected if An error message is displayed for the valid username
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Compare error message responsesCompare the error messages received from both tests - check for differences in wording, timing, or any distinguishing characteristics that indicate different application behavior based on username validityAffected if Different error messages are returned for valid versus invalid usernames
Your environment is affected if the password recovery function returns distinct error messages that allow an attacker to distinguish between valid and invalid usernames.
Generated from the published advisory. Verify against your own configuration.
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 dataImplement generic, identical error messages for both valid and invalid usernames during password recovery. Additionally, implement rate limiting and account lockout mechanisms to mitigate automated enumeration attempts.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-36135 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-36135 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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