SymfonyFramework / library · Sensiolabs
CVE-2017-16652
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 · uneditedAn issue was discovered in Symfony 2.7.x before 2.7.38, 2.8.x before 2.8.31, 3.2.x before 3.2.14, and 3.3.x before 3.3.13. DefaultAuthenticationSuccessHandler or DefaultAuthenticationFailureHandler takes the content of the _target_path parameter and generates a redirect response, but no check is performed on the path, which could be an absolute URL to an external domain. This Open redirect vulnerability can be exploited for example to mount effective phishing attacks.
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 confidenceOpen redirect vulnerability in Symfony's DefaultAuthenticationSuccessHandler and DefaultAuthenticationFailureHandler. These handlers accept a _target_path parameter and generate redirect responses without validating that the path is local, allowing absolute URLs to external domains. This enables phishing attacks by redirecting users to malicious sites after authentication events.
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
SymfonyFramework / library
> 2.7.0, < 2.7.38> 2.8.0, < 2.8.31> 3.2.0, < 3.2.14>= 3.3.0, < 3.3.13
Debian LinuxOperating system
= 8.0CVSS 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
- 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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Identify installed Symfony versionCheck your project's composer.json file for the symfony/symfony version, or run 'composer show symfony/symfony' to see the installed versionAffected if The version falls within 2.7.0-2.7.37, 2.8.0-2.8.30, 3.2.0-3.2.13, or 3.3.0-3.3.12
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Confirm use of form login authenticationLook for firewall configuration in security.yml that uses 'form_login' or check if your application extends DefaultAuthenticationSuccessHandler/DefaultAuthenticationFailureHandlerAffected if Your application uses Symfony's built-in form login mechanism with default authentication handlers
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Check for _target_path usage in authentication flowSearch your codebase for references to '_target_path' parameter in login templates or controller code, or inspect the authentication URLs your login form submits toAffected if Your login flow passes a _target_path parameter without server-side validation that it points to a local path
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Verify redirect behavior accepts external URLsSubmit a login request with _target_path set to an absolute URL like 'https://evil.example.com' and observe if the application redirects to that external domain after authenticationAffected if The application redirects to the external URL provided in _target_path instead of rejecting it or forcing a local path
You are affected if your Symfony version is in the vulnerable range AND your application uses form login with the _target_path feature, and external URLs are accepted as redirect targets.
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 data2.7.382.8.313.2.14
Upgrade Symfony to versions 2.7.38+, 2.8.31+, 3.2.14+, or 3.3.13+ which implement validation ensuring _target_path contains only local paths.
Fix this in Symfony
Scoped from the published advisory
- Consultation1.0 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 $1,664.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2017-16652 — 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-2017-16652 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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- Version or environment caveats, and links to real fixes
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