CVE-2020-5247

Advisory lineage Upstream: 0 Downstream: 12
Modified
Published: 28 Feb 2020, 16:55
Last modified:04 Aug 2024, 08:22

Vulnerability Summary

Overall Risk (default)
medium
30/100
CVSS Score
7.5 HIGH
v3.1 (nvd)
EPSS Score
2.09% LOW
2% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

28 Feb 2020, 16:55
Published
Vulnerability first disclosed
04 Aug 2024, 08:22
Last Modified
Vulnerability information updated

Description

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.

CVSS Metrics

  • v3.1•MEDIUM•Score: 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
  • v2.0•MEDIUM•Score: 5AV:N/AC:L/Au:N/C:N/I:P/A:N

EPSS Trends

Current EPSS score: 2.09%• Percentile: 84%

Techniques & Countermeasures

  • CWE-74•Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

    The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.

  • CWE-113•Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

    The product receives data from an HTTP agent/component (e.g., web server, proxy, browser, etc.), but it does not neutralize or incorrectly neutralizes CR and LF characters before the data is included in outgoing HTTP headers.

Affected Systems

  • debian•debian_linux

    9.0

  • fedoraproject•fedora

    30 | 31 | 32

  • puma•puma

    ≤ 3.12.3 | ≥ 4.0.0, ≤ 4.3.2 | < 3.12.3 | ≥ 4.0.0, < 4.3.2

  • ruby-lang•ruby

    ≤ 2.3.0 | ≥ 2.4.0, ≤ 2.4.7 | ≥ 2.5.0, ≤ 2.5.6 | ≥ 2.6.0, ≤ 2.6.4 | 2.7.0:preview1

References (7)