Cyber Resilience

CVE-2025-59151

Pi-Hole Web Interface ≤ 6.3

Public PoC
Published
27 October 2025
Modified
18 December 2025
Patch / advisory
CVSS Score v3.1 8.2
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L
EPSS Score 0.0041 34th percentile
Risk Priority 61 floored blend · peak EPSS

Summary

CVE-2025-59151 is a high-severity CRLF Injection (CWE-93) vulnerability in Pi-Hole Web Interface. Its CVSS base score is 8.2 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Content Injection (T1659); ranked at the 34th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) and SI-15 (Information Output Filtering) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-59151 is a Carriage Return Line Feed (CRLF) injection vulnerability affecting the Pi-hole Admin Interface, the web-based management interface for Pi-hole, a network-level advertisement and tracker blocking application. Versions prior to 6.3 fail to properly sanitize input during redirects triggered by requests to files ending in the .lp extension. This allows attackers to inject CRLF characters (%0d%0a), manipulating both HTTP response headers and content. The issue is associated with CWE-93 (CRLF Injection) and CWE-113 (HTTP Response Splitting), earning a CVSS v3.1 base score of 8.2 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L).

The vulnerability can be exploited remotely over the network with low complexity, requiring no privileges or user interaction. An attacker sends a crafted request to a .lp endpoint, injecting CRLF sequences to insert arbitrary HTTP headers into the response. This enables attacks such as session fixation, cache poisoning, and circumvention of browser security features like Content Security Policy (CSP) or X-XSS-Protection, primarily impacting integrity with some availability effects.

The Pi-hole web repository advisory (GHSA-5v79-p56f-x7c4) confirms the vulnerability and states it is fixed in version 6.3 through improved input sanitization during redirects. Security practitioners should upgrade to Pi-hole Admin Interface 6.3 or later to mitigate the issue.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-33404Same product: Pi-Hole Web Interface
CVE-2025-53533Same product: Pi-Hole Web Interface
CVE-2026-33405Same product: Pi-Hole Web Interface
CVE-2026-33403Same product: Pi-Hole Web Interface
CVE-2025-32785Same product: Pi-Hole Web Interface
CVE-2026-33406Same product: Pi-Hole Web Interface
CVE-2026-26952Same product: Pi-Hole Web Interface
CVE-2026-26953Same product: Pi-Hole Web Interface
CVE-2026-33765Same product: Pi-Hole Web Interface
CVE-2023-23614Same product: Pi-Hole Web Interface

Affected Assets

pi-hole
web interface
≤ 6.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V3.4.2
  • V4.1.3
  • V1.3.6
  • V4.2.3

Mitigating Controls (NIST 800-53 r5) AI

Input validation directly stops untrusted data containing CRLF sequences from reaching the component that treats CRLF as a delimiter.

Output filtering can neutralize CRLF sequences before they reach HTTP response headers.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input neutralization and validation to block CRLF injection.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect CRLF flaws but does not itself implement the neutralization.

prevents

Secure development lifecycle mandates input validation and output encoding that directly prevents CRLF injection.

prevents

Application security requirements include rules for neutralizing special characters such as CRLF in inputs.

prevents

Secure architecture principles encourage safe handling of untrusted data but do not prescribe specific CRLF controls.

prevents

Secure coding standards explicitly require neutralization of CRLF sequences, fully addressing this weakness.

A.8.15 Logging none match
none

Logging of HTTP traffic can record header-splitting attempts, aiding detection and forensics.

References