What’s Vulnerable › Vulnerabilities

CVE-2020-25613

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 3.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-10-06 · updated 2026-06-17
• Weakness: CWE-444

Description

An issue was discovered in Ruby through 2.5.8, 2.6.x through 2.6.6, and 2.7.x through 2.7.1. WEBrick, a simple HTTP server bundled with Ruby, had not checked the transfer-encoding header value rigorously. An attacker may potentially exploit this issue to bypass a reverse proxy (which also has a poor header check), which may lead to an HTTP Request Smuggling attack.

Affected products

• Fedoraproject Fedora: 32, 33
• Ruby: through 2.5.8; from 2.6.0 through 2.6.6; from 2.7.0 through 2.7.1
• Ruby WEBrick: through 1.6.0

References

• https://github.com/ruby/webrick/commit/8946bb38b4d87549f0d99ed73c62c41933f97cc7
• https://hackerone.com/reports/965267
• https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PFP3E7KXXT3H3KA6CBZPUOGA5VPFARRJ/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YTZURYROG3FFED3TYCQOBV66BS4K6WOV/
• https://security.gentoo.org/glsa/202401-27
• https://security.netapp.com/advisory/ntap-20210115-0008/
• https://www.ruby-lang.org/en/news/2020/09/29/http-request-smuggling-cve-2020-25613/
• https://github.com/ruby/webrick/commit/8946bb38b4d87549f0d99ed73c62c41933f97cc7
• https://hackerone.com/reports/965267
• https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PFP3E7KXXT3H3KA6CBZPUOGA5VPFARRJ/

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