CVE-2016-2049
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 · uneditedexamples/consumer/common.php in JanRain PHP OpenID library (aka php-openid) improperly checks the openid.realm parameter against the SERVER_NAME element in the SERVER superglobal array, which might allow remote attackers to hijack the authentication of arbitrary users via vectors involving a crafted HTTP Host header.
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 confidenceThe JanRain PHP OpenID library's examples/consumer/common.php improperly validates the openid.realm parameter against SERVER_NAME from the SERVER superglobal. An attacker can supply a crafted HTTP Host header to bypass this check, allowing hijacking of authentication sessions for arbitrary users.
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 dataall versionsCVSS 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
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/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 checksWork through these to decide whether this CVE applies to you.
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Locate JanRain PHP OpenID library installationSearch the web server document root and application directories for the 'php-openid' or 'janrain' directory containing the OpenID library files.Affected if The JanRain PHP OpenID library is installed on the server.
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Check for vulnerable example directoryInspect whether the 'examples/consumer/' directory exists within the library installation.Affected if The examples/consumer/ directory exists, indicating the vulnerable example scripts are present.
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Verify common.php is presentConfirm that examples/consumer/common.php file exists in the installation.Affected if The file common.php exists in the examples/consumer/ directory.
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Test web accessibility of example scriptsAttempt to access the example scripts via HTTP request to URLs such as /php-openid/examples/consumer/ or /janrain/examples/consumer/ from the web server.Affected if The example scripts are accessible via HTTP, allowing an attacker to supply a crafted Host header to exploit the realm validation flaw.
The environment is affected if the JanRain PHP OpenID library is installed with its example scripts (examples/consumer/common.php) present and accessible via the web server, since all versions of the library contain the vulnerable code in those examples.
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 dataRemove or disable the example scripts (examples/consumer/) from production deployments, as they are not intended for production use. If these scripts are required, implement strict whitelist-based validation of the realm parameter against trusted domains.
- Consultation1.0 h
- Implementation1.0 h
- Testing1.0 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 $1,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-2049 — 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-2016-2049 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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