CVE-2020-5249

MEDIUM EPSS 72.3%
Published Mar 2, 20206y ago · Modified Jun 17, 20262w ago
6.5 CVSS 3.1
Medium
Find Similar
Published Mar 2, 2020 6y ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
6.5
Exploitability
2.8
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity High
Availability None

Threat Intelligence

EPSS Exploit Probability
72.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 2

CWE-113
CWE-74

Affected Products 2

VendorProductVersionRange
pumapuma* ≤3.12.3
pumapuma*≥4.0.0  –  ≤4.3.2

References 7

  • github.com https://github.com/puma/puma/commit/c22712fc93284a45a93f9ad7023888f3a65524f3
    PatchThird Party Advisory
  • github.com https://github.com/puma/puma/security/advisories/GHSA-33vf-4xgg-9r58
    Third Party Advisory
  • github.com https://github.com/puma/puma/security/advisories/GHSA-84j7-475p-hp8v
    Third Party Advisory
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BMJ3CGZ3DLBJ5WUUKMI5ZFXFJQMXJZIK/
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/DIHVO3CQMU7BZC7FCTSRJ33YDNS3GFPK/
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NJ3LL5F5QADB6LM46GXZETREAKZMQNRD/
  • owasp.org https://owasp.org/www-community/attacks/HTTP_Response_Splitting
    Third Party Advisory

Remediation

  • github.com https://github.com/puma/puma/commit/c22712fc93284a45a93f9ad7023888f3a65524f3
    PatchThird Party Advisory