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Vulnerability details: VCID-pay9-phaz-bbde
Vulnerability ID VCID-pay9-phaz-bbde
Aliases CVE-2025-6442
GHSA-r995-q44h-hr64
Summary Ruby WEBrick read_headers method can lead to HTTP Request/Response Smuggling Ruby WEBrick read_header HTTP Request Smuggling Vulnerability. This vulnerability allows remote attackers to smuggle arbitrary HTTP requests on affected installations of Ruby WEBrick. This issue is exploitable when the product is deployed behind an HTTP proxy that fulfills specific conditions. The specific flaw exists within the read_headers method. The issue results from the inconsistent parsing of terminators of HTTP headers. An attacker can leverage this vulnerability to smuggle arbitrary HTTP requests. Was ZDI-CAN-21876.
Status Published
Exploitability 0.5
Weighted Severity 6.2
Risk 3.1
Affected and Fixed Packages Package Details
Weaknesses (3)
CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
CWE-937 OWASP Top Ten 2013 Category A9 - Using Components with Known Vulnerabilities
CWE-1035 OWASP Top Ten 2017 Category A9 - Using Components with Known Vulnerabilities
System Score Found at
cvssv3 6.5 https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2025-6442.json
epss 0.00074 https://api.first.org/data/v1/epss?cve=CVE-2025-6442
epss 0.00074 https://api.first.org/data/v1/epss?cve=CVE-2025-6442
epss 0.00074 https://api.first.org/data/v1/epss?cve=CVE-2025-6442
epss 0.00074 https://api.first.org/data/v1/epss?cve=CVE-2025-6442
epss 0.00074 https://api.first.org/data/v1/epss?cve=CVE-2025-6442
epss 0.00074 https://api.first.org/data/v1/epss?cve=CVE-2025-6442
epss 0.00074 https://api.first.org/data/v1/epss?cve=CVE-2025-6442
epss 0.00074 https://api.first.org/data/v1/epss?cve=CVE-2025-6442
epss 0.00074 https://api.first.org/data/v1/epss?cve=CVE-2025-6442
cvssv3.1 6.5 https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
cvssv3 6.5 https://github.com/advisories/GHSA-r995-q44h-hr64
cvssv3.1_qr MODERATE https://github.com/advisories/GHSA-r995-q44h-hr64
cvssv3.1 6.5 https://github.com/rubysec/ruby-advisory-db/blob/master/gems/webrick/CVE-2025-6442.yml
generic_textual MODERATE https://github.com/rubysec/ruby-advisory-db/blob/master/gems/webrick/CVE-2025-6442.yml
cvssv3.1 6.5 https://github.com/ruby/webrick
generic_textual MODERATE https://github.com/ruby/webrick
cvssv3 6.5 https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864
cvssv3.1 6.5 https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864
generic_textual MODERATE https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864
ssvc Track https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864
cvssv3.1 6.5 https://nvd.nist.gov/vuln/detail/CVE-2025-6442
generic_textual MODERATE https://nvd.nist.gov/vuln/detail/CVE-2025-6442
cvssv3.1 6.5 https://www.zerodayinitiative.com/advisories/ZDI-25-414
generic_textual MODERATE https://www.zerodayinitiative.com/advisories/ZDI-25-414
cvssv3 6.5 https://www.zerodayinitiative.com/advisories/ZDI-25-414/
ssvc Track https://www.zerodayinitiative.com/advisories/ZDI-25-414/
Reference id Reference type URL
https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2025-6442.json
https://api.first.org/data/v1/epss?cve=CVE-2025-6442
https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
https://github.com/advisories/GHSA-r995-q44h-hr64
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/webrick/CVE-2025-6442.yml
https://github.com/ruby/webrick
https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864
https://nvd.nist.gov/vuln/detail/CVE-2025-6442
https://www.zerodayinitiative.com/advisories/ZDI-25-414
2374895 https://bugzilla.redhat.com/show_bug.cgi?id=2374895
USN-7709-1 https://usn.ubuntu.com/7709-1/
USN-7840-1 https://usn.ubuntu.com/7840-1/
ZDI-25-414 https://www.zerodayinitiative.com/advisories/ZDI-25-414/
No exploits are available.
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N Found at https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2025-6442.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N Found at https://ftp.suse.com/pub/projects/security/yaml/suse-cvss-scores.yaml
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Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N Found at https://github.com/rubysec/ruby-advisory-db/blob/master/gems/webrick/CVE-2025-6442.yml
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N Found at https://github.com/ruby/webrick
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N Found at https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

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Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N Found at https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

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Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-25T20:41:55Z/ Found at https://github.com/ruby/webrick/commit/ee60354bcb84ec33b9245e1d1aa6e1f7e8132101#diff-ad02984d873efb089aa51551bc6b7d307a53e0ba1ac439e91d69c2e58a478864
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N Found at https://nvd.nist.gov/vuln/detail/CVE-2025-6442
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

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Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N Found at https://www.zerodayinitiative.com/advisories/ZDI-25-414
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

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Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N Found at https://www.zerodayinitiative.com/advisories/ZDI-25-414/
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

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Vector: SSVCv2/E:N/A:N/T:P/P:M/B:A/M:M/D:T/2025-06-25T20:41:55Z/ Found at https://www.zerodayinitiative.com/advisories/ZDI-25-414/
Exploit Prediction Scoring System (EPSS)
Percentile 0.22508
EPSS Score 0.00074
Published At April 2, 2026, 12:55 p.m.
Date Actor Action Source VulnerableCode Version
2026-04-01T12:56:46.914859+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/06/GHSA-r995-q44h-hr64/GHSA-r995-q44h-hr64.json 38.0.0