How severe is CVE-2012-6431?

No CVSS score has been assigned to CVE-2012-6431 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2012-6431?

CVE-2012-6431 affects the following packages: symfony/http-foundation (Packagist), symfony/routing (Packagist), symfony/security (Packagist), symfony/symfony (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2012-6431?

Update symfony/http-foundation to 2.0.19 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2012-6431 is resolved across your whole dependency graph.

How do I detect CVE-2012-6431 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symfony/http-foundation, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2012-6431 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2012-6431?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2012-6431 can be triaged on real exposure rather than presence alone.

Is CVE-2012-6431 actively exploited in the wild?

No public exploit code has been indexed for CVE-2012-6431 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2012-6431?

CVE-2012-6431 has an EPSS (Exploit Prediction Scoring System) score of 1.9%, placing it in the 78th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2012-6431?

CVE-2012-6431 is classified as CWE-264 (CWE-264). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2012-6431 published, and has it been updated?

CVE-2012-6431 was published on May 17, 2022 and was last updated on December 3, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

CVE-2012-6431 — symfony/http-foundation

Fix: symfony/symfony@55014a6

CVE-2012-6431 is a CWE-264 vulnerability in symfony/http-foundation. A fix is available for symfony/http-foundation — see the affected versions and patch details below.

Symfony Allows URI Restrictions Bypass Via Double-Encoded String

Published

May 17, 2022

Updated

Dec 3, 2024

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Sep 18, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs78th percentile — riskier than 78% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

4 pkgs affected

🐘symfony/http-foundation🐘symfony/routing🐘symfony/security🐘symfony/symfony

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

On the Symfony 2.0.x version, there's a security issue that allows access to routes protected by a firewall even when the user is not logged in.

Both the Routing component and the Security component uses the path returned by getPathInfo() to match a Request. The getPathInfo() returns a decoded path, but the Routing component (Symfony\Component\Routing\Matcher\UrlMatcher) decodes the path a second time; whereas the Security component, Symfony\Component\HttpFoundation\RequestMatcher, does not.

This difference causes Symfony 2.0 to be vulnerable to double encoding attacks.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`symfony/http-foundation`	≥ 2.0.0&&< 2.0.19	2.0.19`composer require symfony/http-foundation:^2.0.19`
🐘Packagist	`symfony/routing`	≥ 2.0.0&&< 2.0.19	2.0.19`composer require symfony/routing:^2.0.19`
🐘Packagist	`symfony/security`	≥ 2.0.0&&< 2.0.19	2.0.19`composer require symfony/security:^2.0.19`
🐘Packagist	`symfony/symfony`	≥ 2.0.0&&< 2.0.19	2.0.19`composer require symfony/symfony:^2.0.19`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symfony/http-foundation, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update symfony/http-foundation to 2.0.19 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2012-6431 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2012-6431 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2012-6431. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

On the Symfony 2.0.x version, there's a security issue that allows access to routes protected by a firewall even when the user is not logged in. Both the Routing component and the Security component uses the path returned by `getPathInfo()` to match a Request. The `getPathInfo()` returns a decoded path, but the Routing component (`Symfony\Component\Routing\Matcher\UrlMatcher`) decodes the path a second time; whereas the Security component, `Symfony\Component\HttpFoundation\RequestMatcher`, does not. This difference causes Symfony 2.0 to be vulnerable to double encoding attacks.

O3 Security · Impact-Aware SCA

Is CVE-2012-6431 in your dependencies?

O3 Security finds CVE-2012-6431 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works