RCE in Symfony
Published 2 Sept 2020 · Updated 8 Jul 2026
Affected packages
- Affected
- >=4.3.0 <4.4.13
- Fixed in
- 4.4.13
composer require symfony/http-kernel:^4.4.13- Affected
- >=5.0.0 <5.1.5
- Fixed in
- 5.1.5
composer require symfony/http-kernel:^5.1.5- Affected
- >=4.3.0 <4.4.13
- Fixed in
- 4.4.13
composer require symfony/symfony:^4.4.13- Affected
- >=5.0.0 <5.1.5
- Fixed in
- 5.1.5
composer require symfony/symfony:^5.1.5Details
Description -----------
The CachingHttpClient class from the HttpClient Symfony component relies on the HttpCache class to handle requests. HttpCache uses internal headers like X-Body-Eval and X-Body-File to control the restoration of cached responses. The class was initially written with surrogate caching and ESI support in mind (all HTTP calls come from a trusted backend in that scenario). But when used by CachingHttpClient and if an attacker can control the response for a request being made by the CachingHttpClient, remote code execution is possible.
Resolution ----------
HTTP headers designed for internal use in HttpCache are now stripped from remote responses before being passed to HttpCache.
The patch for this issue is available here for the 4.4 branch.
Credits -------
I would like to thank Matthias Pigulla (webfactory GmbH) for reporting and fixing the issue.
Is GHSA-754h-5r27-7x3r in any of your client repos?
Checking one package by hand is fine. Checking it across forty client projects is not. NPMscan reads the lockfiles in every GitHub repo you pick, finds each project with an affected symfony/http-kernel, and gives you the command that fixes it.
References
- Linkgithub.com/symfony/symfony/security/advisories/GHSA-754h-5r27-7x3r
- Advisorynvd.nist.gov/vuln/detail/CVE-2020-15094
- Linkgithub.com/symfony/symfony/commit/d9910e0b33a2e0f993abff41c6fbc86951b66d78
- Linkgithub.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-kernel/CVE-2020-15094.yaml
- Linkgithub.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2020-15094.yaml
- Packagegithub.com/symfony/symfony
- Linklists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/HNGUWOEETOFVH4PN3I3YO4QZHQ4AUKF3
- Linklists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VAQJXAKWPMWB7OL6QPG2ZSEQZYYPU5RC
- Linkpackagist.org/packages/symfony/http-kernel
- Linkpackagist.org/packages/symfony/symfony
- Linksymfony.com/cve-2020-15094
Advisory data from OSV.dev (opens OSV.dev in a new tab), refreshed daily.