Escape Sequence Injection vulnerability in Rack lead to Possible Log Injection

Open Source Vulnerabilities CVE-2025-27111

Rack is a modular Ruby web server interface. The Rack::Sendfile middleware logs unsanitised header values from the X-Sendfile-Type header. An attacker can exploit this by injecting escape sequences (such as newline characters) into the header, resulting in log injection. This vulnerability is fixed in 2.2.12, 3.0.13, and 3.1.11.

Open Source Vulnerabilities GHSA-8cgq-6mh2-7j6v

## Summary `Rack::Sendfile` can be exploited by crafting input that includes newline characters to manipulate log entries. ## Details The `Rack::Sendfile` middleware logs unsanitized header values from the `X-Sendfile-Type` header. An attacker can exploit this by injecting escape sequences (such as newline characters) into the header, resulting in log injection. ## Impact This vulnerability can distort log files, obscure attack traces, and complicate security auditing. ## Mitigation - Update to the latest version of Rack, or - Remove usage of `Rack::Sendfile`.