CVE-2025-61921

LOW EPSS 35.7%
Published Oct 10, 20258mo ago · Modified Jun 17, 20262w ago
2.7 CVSS 4.0
Low
Find Similar
Published Oct 10, 2025 8mo ago
Last Modified Jun 17, 2026 2w ago

Description

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 Details

Base Score
2.7
Exploitability
—
Impact
—
Vector string
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
35.7% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-1333

Affected Products 1

VendorProductVersionRange
sinatrarbsinatra* <4.2.0

References 5

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

Remediation

  • github.com https://github.com/sinatra/sinatra/pull/1823
    ExploitPatch
  • github.com https://github.com/sinatra/sinatra/pull/2121
    Patch