CVE-2025-61921
7.5 · HIGHOverview
CVE-2025-61921 is a high-severity vulnerability affecting sinatrarb sinatra. It was published on October 10, 2025 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from sinatrarb. Update sinatra to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| sinatrarb | sinatra | >= 0, < 4.2.0 | Affected |
Frequently Asked Questions
What is CVE-2025-61921?
CVE-2025-61921 is a high-severity vulnerability affecting sinatrarb sinatra. It was published on October 10, 2025 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2025-61921?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2025-61921?
Check the references section for vendor advisories and patches from sinatrarb. Update sinatra to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-61921?
CyberStrike's AI-powered security agents can automatically detect CVE-2025-61921 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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