CVE-2020-5247 HTTP Response Splitting in Puma

2020-02-2816:55:15

CWE-113

GitHub_M

www.cve.org

6.5 Medium

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality Impact

LOW

Integrity Impact

LOW

Availability Impact

LOW

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

6.7 Medium

AI Score

Confidence

High

0.011 Low

EPSS

Percentile

84.1%

JSON

In Puma (RubyGem) before 4.3.2 and before 3.12.3, if an application using Puma allows untrusted input in a response header, an attacker can use newline characters (i.e. CR, LF or/r, /n) 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-2019-16254, which fixed this vulnerability for the WEBrick Ruby web server. This has been fixed in versions 4.3.2 and 3.12.3 by checking all headers for line endings and rejecting headers with those characters.

CNA Affected

[
  {
    "product": "Puma",
    "vendor": "puma",
    "versions": [
      {
        "status": "affected",
        "version": "< 3.12.3"
      },
      {
        "status": "affected",
        "version": ">= 4.0.0, < 4.3.2"
      }
    ]
  }
]