CVE-2025-59151: web interface — Exploit & Fix

Description

Pi-hole Admin Interface is a web interface for managing Pi-hole, a network-level advertisement and internet tracker blocking application. Pi-hole Admin Interface before 6.3 is vulnerable to Carriage Return Line Feed (CRLF) injection. When a request is made to a file ending with the .lp extension, the application performs a redirect without properly sanitizing the input. An attacker can inject carriage return and line feed characters (%0d%0a) to manipulate both the headers and the content of the HTTP response. This enables the injection of arbitrary HTTP response headers, potentially leading to session fixation, cache poisoning, and the weakening or bypassing of browser-based security mechanisms such as Content Security Policy or X-XSS-Protection. This vulnerability is fixed in 6.3.

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CVSS v3.1 Score

8.2

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L

Weakness Type (CWE)

CWE-93 CWE-93

CWE-113 CWE-113

Affected Products

Vendor	Product	Versions
pi-hole	web_interface	< 6.3

References

Advisories & Patches

https://github.com/pi-hole/web/security/advisories/GHSA-5v79-p56f-x7c4

Exploits

https://github.com/pi-hole/web/security/advisories/GHSA-5v79-p56f-x7c4

Frequently Asked Questions

What is CVE-2025-59151? +

Pi-hole Admin Interface is a web interface for managing Pi-hole, a network-level advertisement and internet tracker blocking application. Pi-hole Admin Interface before 6.3 is vulnerable to Carriage Return Line Feed (CRLF) injection. When a request is made to a file ending with the .lp extension, the application performs a redirect without properly sanitizing the input. An attacker can inject carriage return and line feed characters (%0d%0a) to manipulate both the headers and the content of the HTTP response. This enables the injection of arbitrary HTTP response headers, potentially leading to session fixation, cache poisoning, and the weakening or bypassing of browser-based security mechanisms such as Content Security Policy or X-XSS-Protection. This vulnerability is fixed in 6.3. It has a CVSS v3.1 base score of 8.2 (HIGH).

How severe is CVE-2025-59151? +

CVE-2025-59151 has a CVSS v3.1 score of 8.2 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-59151? +

CVE-2025-59151 affects products from pi-hole, specifically: web_interface. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-59151? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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