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Prevent cache poisoning via a Response Content-Type header in Symfony

Low severity GitHub Reviewed Published Mar 30, 2020 in symfony/symfony • Updated Feb 5, 2024

Package

composer symfony/http-foundation (Composer)

Affected versions

>= 4.4.0, < 4.4.7
>= 5.0.0, < 5.0.7

Patched versions

4.4.7
5.0.7
composer symfony/symfony (Composer)
>= 4.4.0, < 4.4.7
>= 5.0.0, < 5.0.7
4.4.7
5.0.7

Description

Description

When a Response does not contain a Content-Type header, Symfony falls back 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 lead to a corrupted cache where the cached format is not the right one.

Resolution

Symfony does not use the Accept header anymore to guess the Content-Type.

The patch for this issue is available here for the 4.4 branch.

Credits

I would like to thank Xavier Lacot from JoliCode for reporting & Yonel Ceruto and Tobias Schultze for fixing the issue.

References

@nicolas-grekas nicolas-grekas published to symfony/symfony Mar 30, 2020
Reviewed Mar 30, 2020
Published to the GitHub Advisory Database Mar 30, 2020
Last updated Feb 5, 2024

Severity

Low

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(58th percentile)

Weaknesses

Improper Interaction Between Multiple Correctly-Behaving Entities

An interaction error occurs when two entities have correct behavior when running independently of each other, but when they are integrated as components in a larger system or process, they introduce incorrect behaviors that may cause resultant weaknesses. Learn more on MITRE.

CVE ID

CVE-2020-5255

GHSA ID

GHSA-mcx4-f5f5-4859

Source code

No known source code

Credits

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