CVE-2021-20105
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 · uneditedMachform prior to version 16 is vulnerable to an open redirect in Safari_init.php due to an improperly sanitized 'ref' parameter.
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 confidenceMachform before version 16 contains an open redirect vulnerability in Safari_init.php. The 'ref' parameter is not properly sanitized, allowing attackers to craft malicious URLs that redirect users to arbitrary external websites.
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< 16CVSS 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 Machform installation versionLook for version information in the application. Common locations include: a version.php file, a config file, or the main index.php footer. Search for a version constant or variable (often 'VERSION', 'APP_VERSION', or similar) in the web root directory.Affected if The installed version is below 16, or no version file is found and the application predates version 16.
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Locate Safari_init.php fileIn the Machform web root directory, search for the file named Safari_init.php. This file is typically in the main installation directory or in an includes folder.Affected if The file Safari_init.php exists in the Machform installation.
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Inspect Safari_init.php for ref parameter handlingOpen Safari_init.php and search for any usage of the 'ref' parameter. Look for code that retrieves this parameter (from $_GET, $_REQUEST, or similar) and passes it to a redirect function or header operation.Affected if The file contains code that processes a 'ref' parameter without visible sanitization or validation checks.
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Check if ref parameter flows to redirect logicExamine the code around the 'ref' parameter usage. Identify if the parameter value is used in functions like header(), redirect(), or similar redirect mechanisms without proper validation against a whitelist or removal of external URLs.Affected if The 'ref' parameter value is directly used in a redirect without sanitization that prevents external URLs (e.g., http:// or https:// prefixes).
You are affected if Machform is installed with a version below 16 and the Safari_init.php file exists with un-sanitized 'ref' parameter handling that allows external URL redirection.
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 data16
Upgrade to Machform version 16 or later which includes proper sanitization of the 'ref' parameter.
- Consultation2.0 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-2021-20105 — 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-2021-20105 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
- No spam, self-promotion, credentials, or personal data