Vulnerability in Puma
CVE-2020-5249
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.
EPSS: 0.016 (72.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L.
Affected products
- Puma — versions < 3.12.4, >= 4.0.0, < 4.3.3
Weakness classification (CWE)
References
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (x_refsource_FEDORA, vendor-advisory)
- security-advisories@github.com (x_refsource_FEDORA, vendor-advisory)
- security-advisories@github.com (x_refsource_FEDORA, vendor-advisory)
Frequently asked questions
- What is CVE-2020-5249?
- CVE-2020-5249 is a medium-severity vulnerability in Puma, classified under HTTP Response Splitting. CVSS score: 6.5/10. Published 2020-03-02.
- How severe is CVE-2020-5249?
- Medium severity. CVSS v3 base score is 6.5 out of 10.