Full Report
Cybersecurity researchers have disclosed three security flaws in the Rack Ruby web server interface that, if successfully exploited, could enable attackers to gain unauthorized access to files, inject malicious data, and tamper with logs under certain conditions. The vulnerabilities, flagged by cybersecurity vendor OPSWAT, are listed below - CVE-2025-27610 (CVSS score: 7.5) - A path traversal
Analysis Summary
# Vulnerability: Multiple Flaws in Rack Web Server Interface (CVE-2025-27610, CVE-2025-27111, CVE-2025-25184)
## CVE Details
- CVE ID: CVE-2025-27610, CVE-2025-27111, CVE-2025-25184
- CVSS Score: 7.5 (High) for CVE-2025-27610; 6.9 (Medium) for CVE-2025-27111; 5.7 (Medium) for CVE-2025-25184
- CWE: Path Traversal (CWE undisclosed for others, related to CRLF manipulation)
## Affected Systems
- Products: Rack Ruby web server interface (specifically `Rack::Static` middleware)
- Versions: Not explicitly stated, but applies to versions where `Rack::Static` does not properly sanitize paths when the `:root` parameter is undefined or misconfigured.
- Configurations: Affected when `Rack::Static` is used to serve static content and the `:root` parameter is not explicitly defined (defaulting to `Dir.pwd`).
## Vulnerability Description
Three vulnerabilities were disclosed in the Rack Ruby web server interface:
1. **CVE-2025-27610 (Path Traversal, CVSS 7.5):** The `Rack::Static` middleware fails to sanitize user-supplied paths before serving files. If the `:root` option is not explicitly defined, Rack defaults it to the current working directory (`Dir.pwd`). An attacker can use path traversal techniques to access files outside the intended static file directory, potentially leading to unauthorized file disclosure (e.g., configuration files, credentials).
2. **CVE-2025-27111 & CVE-2025-25184 (CRLF Injection in Logs, CVSS 6.9 & 5.7):** These vulnerabilities involve improper neutralization of Carriage Return Line Feed (CRLF) sequences and improper output neutralization for logs. Successful exploitation may allow attackers to manipulate log entries, distort log files, and obscure attack traces.
## Exploitation
- Status: Disclosure suggests unauthenticated access is possible for CVE-2025-27610, indicating potential for exploitation.
- Complexity: Low/Medium (Likely low for path traversal against an unauthenticated endpoint serving static files).
- Attack Vector: Network
## Impact
- Confidentiality: High (Arbitrary file read potentially exposing sensitive data via CVE-2025-27610)
- Integrity: Medium (Log manipulation via CVE-2025-27111/27610)
- Availability: Low (No direct impact to service availability mentioned)
## Remediation
### Patches
- The article advises updating to the latest version of Rack to mitigate the risk. Specific patched versions were not listed in the summary context.
### Workarounds
1. Remove the usage of `Rack::Static`.
2. If `Rack::Static` must be used, ensure the `:root` parameter is explicitly defined and points only to a directory path containing files intended for public access.
## Detection
- **Indicators of Compromise:** Look for unusual file access requests hitting static file endpoints that attempt directory traversal sequences (e.g., `../../etc/passwd`) or file contents appearing unexpectedly in web server access logs (in the case of log injection).
- **Detection Methods and Tools:** Monitor web application logs for abnormal URI requests directed at static file handlers.
## References
- Vendor Advisories: GHSA-7wqh-767x-r66v (CVE-2025-27610), GHSA-7g2v-jj9q-g3rg (CVE-2025-27111), GHSA-8cgq-6mh2-7j6v (CVE-2025-25184)
- Relevant links: opswat dot com/blog/security-analysis-of-rack-ruby-framework-cve-2025-25184-cve-2025-27111-and-cve-2025-27610 (Defanged)