CVE-2019-20225
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 · uneditedMyBB before 1.8.22 allows an open redirect on login.
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 · moderate confidenceMyBB before version 1.8.22 contains an open redirect vulnerability in the login mechanism. Attackers can manipulate the redirect parameter during the authentication process to redirect users to an arbitrary external site after login, potentially leading to phishing 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< 1.8.22CVSS 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
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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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Identify MyBB versionLog into the MyBB admin control panel and navigate to Dashboard or Tools & Settings to view the installed version. Alternatively, check the inc/class_core.php file or any version.php file in the MyBB installation directory for the version number.Affected if The installed version is earlier than 1.8.22 (e.g., 1.8.21, 1.8.20, etc.)
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Locate login redirect handling codeIn the MyBB installation directory, locate the member.php or login-related file that processes the redirect parameter during the authentication process. Look for functions handling the login redirect logic.Affected if The code processes a redirect parameter without validating whether the URL is internal or external.
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Test redirect parameter behaviorSubmit a login request with a crafted redirect parameter pointing to an external domain (e.g., redirect=https://malicious-site.com). After successful authentication, observe whether the application redirects to the external URL provided in the parameter.Affected if The application redirects to the external URL specified in the redirect parameter instead of rejecting it or limiting it to internal paths.
A user is affected if the installed MyBB version is below 1.8.22 AND the login mechanism allows arbitrary external URLs in the redirect parameter without validation.
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 data1.8.22
Upgrade to MyBB version 1.8.22 or later which addresses this vulnerability. If immediate upgrading is not feasible, implement strict validation of redirect URLs to ensure they only point to internal paths.
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-20225 — 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-2019-20225 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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