CVE-2018-6520
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 · uneditedSimpleSAMLphp before 1.15.2 allows remote attackers to bypass an open redirect protection mechanism via crafted authority data in a URL.
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 confidenceThis is an open redirect bypass vulnerability in SimpleSAMLphp versions prior to 1.15.2. Attackers can craft malicious authority data within a URL to circumvent the application's built-in open redirect protection mechanism, potentially redirecting users to malicious sites.
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>= 1.12.0, < 1.15.1CVSS 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:3.0/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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Locate SimpleSAMLphp installation directoryFind the root directory where SimpleSAMLphp is installed. Common locations include /var/simplesamlphp, /www/simplesamlphp, or within a web application's vendor directory. Look for the config.php file or a www/ directory containing SimpleSAMLphp entry points.Affected if The installation directory cannot be located or does not appear to be SimpleSAMLphp
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Identify installed SimpleSAMLphp versionOpen the configuration file (typically config/config.php) and locate the version parameter, or check for a VERSION file in the root SimpleSAMLphp directory. The version may also be in a composer.json file if installed via Composer.Affected if The version found is greater than or equal to 1.12.0 and less than 1.15.1
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Verify redirect handling is in useSearch configuration files for parameters related to URL redirection, such as 'authproc', ' spherelink', or custom authentication processing filters that handle redirect targets. Also check if any modules use the SimpleSAMLphp redirect function with user-supplied URLs.Affected if Redirection logic that accepts user input is configured or implemented in custom modules
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Inspect redirect validation logicExamine the SimpleSAMLphp source code in the lib/Functions directory, specifically the redirect() or validateURL() functions if they exist. Look for how authority data within URLs is parsed and whether it is properly filtered.Affected if The redirect validation appears to lack proper filtering of authority components in URLs or uses a whitelist that can be bypassed
A user is affected if their SimpleSAMLphp installation version is between 1.12.0 and 1.15.1 inclusive and the application processes user-supplied redirect targets through SimpleSAMLphp's redirect functions.
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 data1.15.1
Upgrade SimpleSAMLphp to version 1.15.2 or later to obtain the security fix. Additionally, implement strict URL validation on any user-supplied redirect targets.
- Consultation2.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,328.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-6520 — 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-2018-6520 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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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.
- 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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