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VULNERABILITIES

CVE-2020-5247 Details

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.

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References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.

URLSource(s)Tag(s)
https://github.com/puma/puma/security/advisories/GHSA-84j7-475p-hp8v CVEMitigationThird Party Advisory
https://lists.debian.org/debian-lts-announce/2022/05/msg00034.html CVEMailing ListThird Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BMJ3CGZ3DLBJ5WUUKMI5ZFXFJQMXJZIK/ CVE
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DIHVO3CQMU7BZC7FCTSRJ33YDNS3GFPK/ CVE
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NJ3LL5F5QADB6LM46GXZETREAKZMQNRD/ CVE

see all 14 references

Weakness Enumeration

CWE-IDCWE NameSource
CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')[email protected]
CWE-113Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')[email protected]

Affected Products

ProductVersions
puma puma
<= 3.12.3
>= 4.0.0, <= 4.3.2

CPE

  • cpe:2.3:a:puma:puma:*:*:*:*:*:ruby:*:*

Remediation

  • No remediation found in references.
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

CPE

  • cpe:2.3:a:ruby-lang:ruby:*:*:*:*:*:*:*:*
  • cpe:2.3:a:ruby-lang:ruby:2.7.0:preview1:*:*:*:*:*:*

Remediation

  • No remediation found in references.
debian debian linux
9.0

CPE

  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

Remediation

  • No remediation found in references.
fedoraproject fedora
30
31
32

CPE

  • cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
  • cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
  • cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*

Remediation

  • No remediation found in references.

Change History

10 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2020-5247
NVD Published Date:
Feb 28, 2020
NVD Last Modified:
Jun 17, 2026
Source:
[email protected]
CVE-2020-5247 Details - Not Deferred