CVE-2020-5249 - CVE House
Back to Database
Status published Medium CVE-2020-5249

HTTP Response Splitting (Early Hints) in Puma

Vulnerability Description

In Puma (RubyGem) before 4.3.3 and 3.12.4, if an application using Puma allows untrusted input in an early-hints header, an attacker can use a carriage return character to end the header and inject malicious content, such as additional headers or an entirely new response body. This vulnerability is known as HTTP Response Splitting. While not an attack in itself, response splitting is a vector for several other attacks, such as cross-site scripting (XSS). This is related to CVE-2020-5247, which fixed this vulnerability but only for regular responses. This has been fixed in 4.3.3 and 3.12.4.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

THREAT MONITOR

Am I Vulnerable?

Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2020-5249

Credits & Attribution

No credits recorded in the NVD database.

References

More from puma

View All →
CVE-2024-45614
Header normalization allows for client to clobber proxy set headers in Puma
Medium 5.4
CVE-2024-21647
HTTP Request/Response Smuggling in puma
Medium 5.9
CVE-2023-40175
Inconsistent Interpretation of HTTP Requests in puma
High 7.3
CVE-2022-24790
HTTP Request Smuggling in puma
Critical 9.1
CVE-2022-23634
Information Exposure when using Puma with Rails
High 8

Affected Vendor

Affected Software

Puma
Vulnerable Versions:
< 3.12.4, >= 4.0.0, < 4.3.3

Timeline

Official Publish: March 2nd, 2020
Last Modified: August 4th, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L

Weaknesses (CWE)

CWE-113

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.