CVE-2020-5255 Prevent cache poisoning via a Response Content-Type header

What is CVE-2020-5255?

CVE-2020-5255 is a low-severity vulnerability in Sensiolabs Symfony, published on 30 Mar 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

In Symfony before versions 4.4.7 and 5.0.7, when a `Response` does not contain a `Content-Type` header, affected versions of Symfony can fallback to the format defined in the `Accept` header of the request, leading to a possible mismatch between the response's content and `Content-Type` header. When the response is cached, this can prevent the use of the website by other users. This has been patched in versions 4.4.7 and 5.0.7.

Weakness: CWE-20, CWE-435

Which versions are affected by CVE-2020-5255?

9 open source packages ship an affected version, including symfony/http-foundation, symfony and symfony/symfony. It affects 1 product.

Products include Sensiolabs Symfony.

How do I fix CVE-2020-5255?

Upgrade symfony/http-foundation to a fixed version for your release line: 4.4.7 or 5.0.7.

Is CVE-2020-5255 being exploited?

There is no known exploitation of CVE-2020-5255 in the wild and no public exploit code.

Other vulnerabilities in Sensiolabs Symfony

• CVE-2019-11325 Improper Input Validation in Symfony Critical 9.8
• CVE-2017-11365 Symfony Incorrect Access Control Critical 9.8
• CVE-2019-10913 Invalid HTTP method overrides allow possible XSS or other attacks in Symfony Critical 9.8
• CVE-2018-11407 Symfony Authentication Bypass Critical 9.8
• CVE-2016-2403 Symfony Authentication Bypass Critical 9.8

All Sensiolabs Symfony vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-symfony-2020-5255, DEBIAN-CVE-2020-5255, GHSA-mcx4-f5f5-4859.