What is CVE-2018-14773?

CVE-2018-14773 is a medium-severity security vulnerability in symfony/http-foundation (composer), affecting versions >= 2.7.0, < 2.7.49. It is fixed in 2.7.49, 2.8.44, 3.3.18, 3.4.14, 4.0.14, 4.1.3.

How severe is CVE-2018-14773?

CVE-2018-14773 has a CVSS score of 6.5 (Medium). 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-2018-14773?

symfony/http-foundation (composer) versions >= 2.7.0, = 2.7.0, < 2.7.49.

Is there a fix for CVE-2018-14773?

Yes. CVE-2018-14773 is fixed in 2.7.49, 2.8.44, 3.3.18, 3.4.14, 4.0.14, 4.1.3. Upgrade to this version or later.

Is CVE-2018-14773 exploitable, and should I be worried?

Whether CVE-2018-14773 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.

What actually determines whether CVE-2018-14773 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.

CVE-2018-14773 in symfony/http-foundation

Q: How severe is CVE-2018-14773?

CVE-2018-14773 has a CVSS score of 6.5 (Medium). 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.

Q: Which packages are affected by CVE-2018-14773?

symfony/http-foundation (composer) versions >= 2.7.0, = 2.7.0, < 2.7.49.

Q: Is there a fix for CVE-2018-14773?

Yes. CVE-2018-14773 is fixed in 2.7.49, 2.8.44, 3.3.18, 3.4.14, 4.0.14, 4.1.3. Upgrade to this version or later.

Q: Is CVE-2018-14773 exploitable, and should I be worried?

Whether CVE-2018-14773 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.

Q: What actually determines whether CVE-2018-14773 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.

Q: How do I fix CVE-2018-14773?

Upgrade: symfony/http-foundation to 2.7.49 or later, symfony/http-foundation to 2.8.44 or later, symfony/http-foundation to 3.3.18 or later, symfony/http-foundation to 3.4.14 or later, symfony/http-foundation to 4.0.14 or later, symfony/http-foundation to 4.1.3 or later, symfony/symfony to 2.7.49 or later, symfony/symfony to 2.8.44 or later, symfony/symfony to 3.3.18 or later, symfony/symfony to 3.4.14 or later, symfony/symfony to 4.0.14 or later, symfony/symfony to 4.1.3 or later.

Summary

Symfony HTTP Foundation web cache poisoning

An issue was discovered in Http Foundation in Symfony 2.7.0 through 2.7.48, 2.8.0 through 2.8.43, 3.3.0 through 3.3.17, 3.4.0 through 3.4.13, 4.0.0 through 4.0.13, and 4.1.0 through 4.1.2. It arises from support for a (legacy) IIS header that lets users override the path in the request URL via the X-Original-URL or X-Rewrite-URL HTTP request header. These headers are designed for IIS support, but it's not verified that the server is in fact running IIS, which means anybody who can send these requests to an application can trigger this. This affects \Symfony\Component\HttpFoundation\Request::prepareRequestUri() where X-Original-URL and X_REWRITE_URL are both used. The fix drops support for these methods so that they cannot be used as attack vectors such as web cache poisoning.

Impact

CVE-2018-14773 has a CVSS score of 6.5 (Medium). The vector is network-reachable, low 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 (2.7.49, 2.8.44, 3.3.18, 3.4.14, 4.0.14, 4.1.3); upgrading removes the vulnerable code path.

Affected versions

symfony/http-foundation (>= 2.7.0, < 2.7.49) symfony/http-foundation (>= 2.8.0, < 2.8.44) symfony/http-foundation (>= 3.0.0, < 3.3.18) symfony/http-foundation (>= 3.4.0, < 3.4.14) symfony/http-foundation (>= 4.0.0, < 4.0.14) symfony/http-foundation (>= 4.1.0, < 4.1.3) symfony/symfony (>= 2.7.0, < 2.7.49) symfony/symfony (>= 2.8.0, < 2.8.44) symfony/symfony (>= 3.0.0, < 3.3.18) symfony/symfony (>= 3.4.0, < 3.4.14) symfony/symfony (>= 4.0.0, < 4.0.14) symfony/symfony (>= 4.1.0, < 4.1.3)

Security releases

symfony/http-foundation → 2.7.49 (composer) symfony/http-foundation → 2.8.44 (composer) symfony/http-foundation → 3.3.18 (composer) symfony/http-foundation → 3.4.14 (composer) symfony/http-foundation → 4.0.14 (composer) symfony/http-foundation → 4.1.3 (composer) symfony/symfony → 2.7.49 (composer) symfony/symfony → 2.8.44 (composer) symfony/symfony → 3.3.18 (composer) symfony/symfony → 3.4.14 (composer) symfony/symfony → 4.0.14 (composer) symfony/symfony → 4.1.3 (composer)

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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Remediation advice

Upgrade the following packages to resolve this vulnerability:

symfony/http-foundation to 2.7.49 or later; symfony/http-foundation to 2.8.44 or later; symfony/http-foundation to 3.3.18 or later; symfony/http-foundation to 3.4.14 or later; symfony/http-foundation to 4.0.14 or later; symfony/http-foundation to 4.1.3 or later; symfony/symfony to 2.7.49 or later; symfony/symfony to 2.8.44 or later; symfony/symfony to 3.3.18 or later; symfony/symfony to 3.4.14 or later; symfony/symfony to 4.0.14 or later; symfony/symfony to 4.1.3 or later

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently Asked Questions

What is CVE-2018-14773? CVE-2018-14773 is a medium-severity security vulnerability in symfony/http-foundation (composer), affecting versions >= 2.7.0, < 2.7.49. It is fixed in 2.7.49, 2.8.44, 3.3.18, 3.4.14, 4.0.14, 4.1.3.
How severe is CVE-2018-14773? CVE-2018-14773 has a CVSS score of 6.5 (Medium). 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-2018-14773?
- symfony/http-foundation (composer) (versions >= 2.7.0, < 2.7.49)
- symfony/symfony (composer) (versions >= 2.7.0, < 2.7.49)
Is there a fix for CVE-2018-14773? Yes. CVE-2018-14773 is fixed in 2.7.49, 2.8.44, 3.3.18, 3.4.14, 4.0.14, 4.1.3. Upgrade to this version or later.
Is CVE-2018-14773 exploitable, and should I be worried? Whether CVE-2018-14773 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-2018-14773 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-2018-14773?
- Upgrade symfony/http-foundation to 2.7.49 or later
- Upgrade symfony/http-foundation to 2.8.44 or later
- Upgrade symfony/http-foundation to 3.3.18 or later
- Upgrade symfony/http-foundation to 3.4.14 or later
- Upgrade symfony/http-foundation to 4.0.14 or later
- Upgrade symfony/http-foundation to 4.1.3 or later
- Upgrade symfony/symfony to 2.7.49 or later
- Upgrade symfony/symfony to 2.8.44 or later
- Upgrade symfony/symfony to 3.3.18 or later
- Upgrade symfony/symfony to 3.4.14 or later
- Upgrade symfony/symfony to 4.0.14 or later
- Upgrade symfony/symfony to 4.1.3 or later

Other vulnerabilities in symfony/http-foundation

CVE-IDSeverityPackage summary

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