Summary
Symfony allows direct access of ESI URLs behind a trusted proxy
All 2.2.X, 2.3.X, 2.4.X, and 2.5.X versions of the Symfony HttpKernel component are affected by this security issue. Your application is vulnerable only if the ESI feature is enabled and there is a proxy in front of the web application.
This issue has been fixed in Symfony 2.3.19, 2.4.9, and 2.5.4. Note that no fixes are provided for Symfony 2.2 as it is not maintained anymore.
Description
When you enable the ESI feature and when you are using a proxy like Varnish that you configured as a trusted proxy, the FragmentHandler considered requests to render fragments as coming from a trusted source, even if the client was requesting them directly. Symfony can not distinguish between ESI requests done on behalf of the client by Varnish and faked fragment requests coming directly from the client.
To mitigate this issue, and for not-supported Symfony versions, you can use the following workaround in your Varnish configuration (/_fragment being the URL path prefix configured under the fragment setting of the framework bundle configuration):
Copy
sub vcl_recv {
if (req.restarts == 0 && req.url ~ "^/_fragment") {
error 400;
}
}
Resolution
We do not rely on trusted IPs anymore when validating a fragment request as all fragment URLs are now signed.
The patch for this issue is available here: https://github.com/symfony/symfony/pull/11831
Impact
CVE-2014-5245 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.3.19, 2.4.9, 2.5.4); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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See it in your environmentNew to Kodem? Get a demo →Remediation advice
symfony/http-kernel to 2.3.19 or later; symfony/http-kernel to 2.4.9 or later; symfony/http-kernel to 2.5.4 or later; symfony/symfony to 2.3.19 or later; symfony/symfony to 2.4.9 or later; symfony/symfony to 2.5.4 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2014-5245? CVE-2014-5245 is a high-severity security vulnerability in symfony/http-kernel (composer), affecting versions >= 2.0.0, < 2.3.19. It is fixed in 2.3.19, 2.4.9, 2.5.4.
- How severe is CVE-2014-5245? CVE-2014-5245 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which packages are affected by CVE-2014-5245?
symfony/http-kernel(composer) (versions >= 2.0.0, < 2.3.19)symfony/symfony(composer) (versions >= 2.0.0, < 2.3.19)
- Is there a fix for CVE-2014-5245? Yes. CVE-2014-5245 is fixed in 2.3.19, 2.4.9, 2.5.4. Upgrade to this version or later.
- Is CVE-2014-5245 exploitable, and should I be worried? Whether CVE-2014-5245 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2014-5245 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2014-5245?
- Upgrade
symfony/http-kernelto 2.3.19 or later - Upgrade
symfony/http-kernelto 2.4.9 or later - Upgrade
symfony/http-kernelto 2.5.4 or later - Upgrade
symfony/symfonyto 2.3.19 or later - Upgrade
symfony/symfonyto 2.4.9 or later - Upgrade
symfony/symfonyto 2.5.4 or later
- Upgrade