#VU105795 Improper Output Neutralization for Logs in Rack - CVE-2025-27111

Vulnerability identifier: #VU105795

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-27111

CWE-ID: CWE-117

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Rack
Web applications / Modules and components for CMS

Vendor: Rack

Description

The vulnerability allows a remote attacker to manipulate log entries.

The vulnerability exists due to improper input validation of the X-Sendfile-Type header in Rack::Sendfile when handling. A remote attacker can send specially crafted data containing newline characters via the affected header and manipulate log files.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Rack: 2.2.0 - 2.2.11, 3.0.0 - 3.0.12, 3.1.0 - 3.1.10

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External links
https://github.com/rack/rack/commit/803aa221e8302719715e224f4476e438f2531a53
https://github.com/rack/rack/commit/aeac570bb8080ca7b53b7f2e2f67498be7ebd30b
https://github.com/rack/rack/commit/b13bc6bfc7506aca3478dc5ac1c2ec6fc53f82a3
https://github.com/rack/rack/security/advisories/GHSA-8cgq-6mh2-7j6v

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.