CVE-2025-61921

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.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://bugs.ruby-lang.org/issues/19104	Issue Tracking
https://github.com/sinatra/sinatra/issues/2120	Issue Tracking
https://github.com/sinatra/sinatra/pull/1823	Exploit Patch
https://github.com/sinatra/sinatra/pull/2121	Patch
https://github.com/sinatra/sinatra/security/advisories/GHSA-mr3q-g2mv-mr4q	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:sinatrarb:sinatra:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2025-10-10 20:15

Updated : 2025-10-31 16:27

NVD link : CVE-2025-61921

Mitre link : CVE-2025-61921

CVE.ORG link : CVE-2025-61921

JSON object : View

Products Affected

sinatrarb

sinatra

CWE

CWE-1333

Inefficient Regular Expression Complexity

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