UBUNTU-CVE-2025-61921 (CVE-2025-61921)

Vulnerability from osv_ubuntu – Published: 2025-10-10 20:15 – Updated: 2026-07-30 23:12 – Source website
VLAI
Details

Sinatra is a domain-specific language for creating web applications in Ruby. In versions prior to 4.2.0, there is a denial of service vulnerability in the If-Match and If-None-Match header parsing component of Sinatra, if the etag method is used when constructing the response. Carefully crafted input can cause If-Match and If-None-Match header parsing in Sinatra to take an unexpected amount of time, possibly resulting in a denial of service attack vector. This header is typically involved in generating the ETag header value. Any applications that use the etag method when generating a response are impacted. Version 4.2.0 fixes the issue.

Severity
2.7 (Low)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "ruby-sinatra",
            "binary_version": "1.4.7-3ubuntu0.1~esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "ruby-sinatra",
        "purl": "pkg:deb/ubuntu/ruby-sinatra@1.4.7-3ubuntu0.1~esm3?arch=source\u0026distro=esm-apps-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.7-3ubuntu0.1~esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.4.6-2",
        "1.4.7-3",
        "1.4.7-3ubuntu0.1~esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "ruby-sinatra",
            "binary_version": "1.4.8-1ubuntu0.1~esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "ruby-sinatra",
        "purl": "pkg:deb/ubuntu/ruby-sinatra@1.4.8-1ubuntu0.1~esm3?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.4.8-1ubuntu0.1~esm3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.4.7-5",
        "1.4.8-1",
        "1.4.8-1ubuntu0.1~esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "ruby-rack-protection",
            "binary_version": "2.0.8.1-2+deb11u1ubuntu0.1~esm1"
          },
          {
            "binary_name": "ruby-sinatra",
            "binary_version": "2.0.8.1-2+deb11u1ubuntu0.1~esm1"
          },
          {
            "binary_name": "ruby-sinatra-contrib",
            "binary_version": "2.0.8.1-2+deb11u1ubuntu0.1~esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "ruby-sinatra",
        "purl": "pkg:deb/ubuntu/ruby-sinatra@2.0.8.1-2+deb11u1ubuntu0.1~esm1?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.0.8.1-2+deb11u1ubuntu0.1~esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.0.8.1-2",
        "2.0.8.1-2+deb11u1build0.22.04.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "ruby-rack-protection",
            "binary_version": "4.2.1-1"
          },
          {
            "binary_name": "ruby-sinatra",
            "binary_version": "4.2.1-1"
          },
          {
            "binary_name": "ruby-sinatra-contrib",
            "binary_version": "4.2.1-1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "ruby-sinatra",
        "purl": "pkg:deb/ubuntu/ruby-sinatra@4.2.1-1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.2.1-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.1.1-5"
      ]
    }
  ],
  "aliases": [],
  "details": "Sinatra is a domain-specific language for creating web applications in Ruby. In versions prior to 4.2.0, there is a denial of service vulnerability in the `If-Match` and `If-None-Match` header parsing component of Sinatra, if the `etag` method is used when constructing the response. Carefully crafted input can cause `If-Match` and `If-None-Match` header parsing in Sinatra to take an unexpected amount of time, possibly resulting in a denial of service attack vector. This header is typically involved in generating the `ETag` header value. Any applications that use the `etag` method when generating a response are impacted. Version 4.2.0 fixes the issue.",
  "id": "UBUNTU-CVE-2025-61921",
  "modified": "2026-07-30T23:12:19Z",
  "published": "2025-10-10T20:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2025-61921"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-61921"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/sinatra/sinatra/security/advisories/GHSA-mr3q-g2mv-mr4q"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8624-1"
    }
  ],
  "related": [
    "USN-8624-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U",
      "type": "CVSS_V4"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2025-61921"
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.