CVE-2020-25613: Webrick WEBRick Vulnerable To HTTP Request/Response Vulnerability

HIGH
Advisory Identifier: GHSA-gwfg-cqmg-cf8f
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CVSS 7.5
CWE-444
Published
Advisory Summary

CVE-2020-25613 is a HIGH (CVSS 7.5) webrick vulnerable to http request/response vulnerability (CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')) affecting Webrick libraries in the RubyGems ecosystem. The issue involves webrick vulnerable to http request/response smuggling. Remediation is available by upgrading affected packages to version 1.6.1, 1.5.1, 1.4.4.

CVE-2020-25613 at a Glance

CVE Identifier CVE-2020-25613
GHSA Identifier GHSA-gwfg-cqmg-cf8f
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Affected Product Webrick
Package Ecosystem RubyGems
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2020-25613

To remediate this vulnerability, upgrade all affected Webrick dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

webrick fixed: 1.6.1 
Upgrade webrick to 1.6.1
webrick fixed: 1.5.1 
Upgrade webrick to 1.5.1
webrick fixed: 1.4.4 
Upgrade webrick to 1.4.4
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for webrick

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-25613, inspect your project dependencies for Webrick:

inspect dependencies for webrick

Analyze the terminal output to locate any version of Webrick in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.6.1), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling'), where the product acts as an intermediary http agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed http requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination. In Webrick, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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.

CVE-2020-25613 Affected Webrick Versions

3 component(s)
Fixed Versions:
1.6.11.5.11.4.4
Product / Package Ecosystem Affected Versions Fixed Version
webrick
gem/webrick
RubyGems
≥ 1.6.0
< 1.6.1
All 1 versions
1.6.0
1.6.1
webrick
gem/webrick
RubyGems
≥ 1.5.0
< 1.5.1
All 1 versions
1.5.0
1.5.1
webrick
gem/webrick
RubyGems
< 1.4.4
1.4.4

References

NVD — CVE-2020-25613 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-25613
Security Fix Commit FIX COMMIT
https://github.com/ruby/webrick/commit/076ac636bf48b7a492887ce4de7041de23e6c00d
Security Fix Commit FIX COMMIT
https://github.com/ruby/webrick/commit/7618049fa57ddad2efff2a7bc7dad7d2d8a311b1
Security Fix Commit FIX COMMIT
https://github.com/ruby/webrick/commit/8946bb38b4d87549f0d99ed73c62c41933f97cc7
Security Fix Commit FIX COMMIT
https://github.com/ruby/webrick/commit/af2efdcdf826f25592202d187c53963e7932e4b9
hackerone.com/reports/965267 WEB
https://hackerone.com/reports/965267
Webrick Source Repository REPOSITORY
https://github.com/ruby/webrick
Webrick Source Repository REPOSITORY
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/webrick/CVE-2020-25613.yml
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PFP3E7KXXT3H3KA6CBZPUOGA5VPFARRJ
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YTZURYROG3FFED3TYCQOBV66BS4K6WOV
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PFP3E7KXXT3H3KA6CBZPUOGA5VPFARRJ
lists.fedoraproject.org/archives/list/packa... WEB
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/YTZURYROG3FFED3TYCQOBV66BS4K6WOV
Webrick Security Information SECURITY
https://security.gentoo.org/glsa/202401-27
Webrick Security Information SECURITY
https://security.netapp.com/advisory/ntap-20210115-0008
www.ruby-lang.org/en/news/2020/09/29/... WEB
https://www.ruby-lang.org/en/news/2020/09/29/http-request-smuggling-cve-2020-25613

Frequently Asked Questions

What is CVE-2020-25613?
CVE-2020-25613 is a security vulnerability in Webrick involving WEBRick vulnerable to HTTP Request/Response Smuggling under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling').
Which Webrick versions are affected?
Affected versions include releases prior to 1.6.1, 1.5.1, 1.4.4 across affected packages: webrick.
What version fixes CVE-2020-25613?
Upgrading to 1.6.1, 1.5.1, 1.4.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is webrick affected?
Yes, webrick is affected in releases prior to 1.6.1, 1.5.1, 1.4.4. Upgrade your dependency to 1.6.1, 1.5.1, 1.4.4 or later.
What is the CVSS score of CVE-2020-25613?
CVE-2020-25613 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
What CWE is associated with CVE-2020-25613?
CVE-2020-25613 is classified under CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') (The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.).
How can I check RubyGems dependencies for CVE-2020-25613?
Run the dependency tree command: 'inspect dependencies for webrick'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-gwfg-cqmg-cf8f",
  "modified" : "2025-05-29T23:03:56Z",
  "published" : "2022-05-24T17:30:10Z",
  "aliases" : [ "CVE-2020-25613" ],
  "summary" : "WEBRick vulnerable to HTTP Request/Response Smuggling",
  "details" : "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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "webrick"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.6.0"
      }, {
        "fixed" : "1.6.1"
      } ]
    } ],
    "versions" : [ "1.6.0" ]
  }, {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "webrick"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.5.0"
      }, {
        "fixed" : "1.5.1"
      } ]
    } ],
    "versions" : [ "1.5.0" ]
  }, {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "webrick"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.4.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-25613"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ruby/webrick/commit/076ac636bf48b7a492887ce4de7041de23e6c00d"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ruby/webrick/commit/7618049fa57ddad2efff2a7bc7dad7d2d8a311b1"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ruby/webrick/commit/8946bb38b4d87549f0d99ed73c62c41933f97cc7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ruby/webrick/commit/af2efdcdf826f25592202d187c53963e7932e4b9"
  }, {
    "type" : "WEB",
    "url" : "https://hackerone.com/reports/965267"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/ruby/webrick"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/webrick/CVE-2020-25613.yml"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PFP3E7KXXT3H3KA6CBZPUOGA5VPFARRJ"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YTZURYROG3FFED3TYCQOBV66BS4K6WOV"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/PFP3E7KXXT3H3KA6CBZPUOGA5VPFARRJ"
  }, {
    "type" : "WEB",
    "url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/YTZURYROG3FFED3TYCQOBV66BS4K6WOV"
  }, {
    "type" : "WEB",
    "url" : "https://security.gentoo.org/glsa/202401-27"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20210115-0008"
  }, {
    "type" : "WEB",
    "url" : "https://www.ruby-lang.org/en/news/2020/09/29/http-request-smuggling-cve-2020-25613"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-444" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-03-08T19:59:16Z",
    "nvd_published_at" : "2020-10-06T13:15:00Z"
  }
}