CVE-2018-14773
MediumSymfony HTTP Foundation web cache poisoning
Published May 13, 2022 · Updated Aug 7, 2026 · Also known as DEBIAN-CVE-2018-14773, DSA-4441-1, GHSA-8wgj-6wx8-h5hq, UBUNTU-CVE-2018-14773
Key Facts
Patch immediately- CVE-2018-14773 is a medium-severity vulnerability (CVSS 6.5 v3.1) affecting Drupal, Symfony (Sensiolabs), Debian Linux and 2 more products.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 58% probability of exploitation in the next 30 days.
- Fixed versions are available, including Drupal 8.5.6-1, Drupal 8.5.6, Symfony <=2.7.48.
- Brandefense priority: patch immediately, because it is very likely to be exploited soon.
CVSS v3.1
6.5
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
EPSS (30-day exploit likelihood)
58%
Higher than 99.0% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
Get the full CVE-2018-14773 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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.
Affected Products
20 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| DrupalDrupal | See advisory | 8.5.6 |
| SymfonySensiolabs | See advisory | 2.7.48 |
| Debian LinuxDebian | 8.0, 9.0 | n/a |
| symfony/http-foundationcomposer | >= 4.1.0 | 4.1.3 |
| symfony/symfonycomposer | >= 4.1.0 | 4.1.3 |
Patched Releases
Drupal
8.5.6-1, 8.5.6
Symfony
<=2.7.48, 2.3.21+dfsg-4+deb8u4, 2.8.7+dfsg-1.3+deb9u2, 3.4.14+dfsg-1
symfony/http-foundation
2.7.49, 2.8.44, 3.3.18, 3.4.14, 4.0.14, 4.1.3
symfony/symfony
2.7.49, 2.8.44, 3.3.18, 3.4.14, 4.0.14, 4.1.3
Timeline
Publicly disclosed
May 13, 2022
Last updated
Aug 7, 2026
Weakness Type
- CWE-349 Acceptance of Extraneous Untrusted Data With Trusted Data
References
- advisoryGHSA advisory
- advisoryhttps://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-foundation/CVE-2018-14773.yaml
- advisoryhttps://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2018-14773.yaml
- advisory[debian-lts-announce] 20190310 [SECURITY] [DLA 1707-1] symfony security update
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2018-14773
FAQ
Common Questions.
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.
Affected: Drupal; Symfony (Sensiolabs); Debian Linux versions 8.0, 9.0, among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including Drupal 8.5.6-1, Drupal 8.5.6, Symfony <=2.7.48.
Brandefense priority: patch immediately, because it is very likely to be exploited soon.
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