Skip to main content

Pi Hole CVE-2021-32706

HIGH
Code Injection (CWE-94)
2021-08-04 security-advisories@github.com
8.8
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Code injection prevention, sandbox exec
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Initial Access

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 8.8 (HIGH). Attack characteristics: network attack vector, low complexity, low privileges required, no user interaction not required. Public proof-of-concept exploit code is available.

Exploit ScenarioDerived

A remote attacker could inject and execute arbitrary code within the application by sending crafted requests to the affected application.

This Week Schedule remediation this week. Why: HIGH severity + EPSS > 10%.
No patch listed yet 60.2% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAI

Pi-hole's Web interface provides a central location to manage a Pi-hole instance and review performance statistics. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. Public exploit code available and no vendor patch available.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Never evaluate user-controlled input as code. Use sandboxing, disable dangerous functions, apply strict input validation.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Code Injection (CWE-94), which allows attackers to inject and execute arbitrary code within the application. Pi-hole's Web interface provides a central location to manage a Pi-hole instance and review performance statistics. Prior to Pi-hole Web interface version 5.5.1, the validDomainWildcard preg_match filter allows a malicious character through that can be used to execute code, list directories, and overwrite sensitive files. The issue lies in the fact that one of the periods is not escaped, allowing any character to be used in its place. A patch for this vulnerability was released in version 5.5.1. Affected products include: Pi-Hole. Version information: version 5.5.1.

Know when Pi Hole gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

NVD PRIMARY 8.8 HIGH
AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

DescriptionNVD

Pi-hole's Web interface provides a central location to manage a Pi-hole instance and review performance statistics. Prior to Pi-hole Web interface version 5.5.1, the validDomainWildcard preg_match filter allows a malicious character through that can be used to execute code, list directories, and overwrite sensitive files. The issue lies in the fact that one of the periods is not escaped, allowing any character to be used in its place. A patch for this vulnerability was released in version 5.5.1.

Threat Intelligence Overview

EPSS Score
60.2%
Top 1% exploitable
Exploit
POC
Public exploit code exists
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC Yes
EPSS 60.2%
Patch available No
Active threat Yes
Deciding rule
HIGH severity + EPSS > 10%
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
Poc
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

124
Low Medium High Critical
KEV: 0
EPSS: +60
CVSS: +44
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Code Injection CRITICAL

Code injection occurs when an application accepts user input and passes it directly into a language interpreter or evaluator without proper sanitization.

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.

Affected Products (CPE)NVD

cpe:2.3:a:pi-hole:pi-hole:*:*:*:*:*:*:*:*
CVE-2025-34087 HIGH POC
8.8 Jul 03

Pi-hole versions up to 3.3 contain an authenticated command injection via the domain allowlist functionality. When addin

CVE-2020-11108 HIGH POC
8.8 May 11

The Gravity updater in Pi-hole through 4.4 allows an authenticated adversary to upload arbitrary files. Rated high sever

CVE-2021-29449 MEDIUM POC
6.3 Apr 14

Pi-hole is a Linux network-level advertisement and Internet tracker blocking application. Rated medium severity (CVSS 6.

CVE-2020-8816 HIGH POC
7.2 May 29

Pi-hole Web v4.3.2 (aka AdminLTE) allows Remote Code Execution by privileged dashboard users via a crafted DHCP static l

CVE-2024-34361 HIGH POC
8.8 Jul 05

Pi-hole is a DNS sinkhole that protects devices from unwanted content without installing any client-side software. Rated

CVE-2023-23614 HIGH POC
8.8 Jan 26

Pi-hole®'s Web interface (based off of AdminLTE) provides a central location to manage your Pi-hole. Rated high severity

CVE-2021-29448 HIGH POC
8.8 Apr 15

Pi-hole is a Linux network-level advertisement and Internet tracker blocking application. Rated high severity (CVSS 8.8)

CVE-2025-59151 HIGH POC
8.2 Oct 27

HTTP response splitting in Pi-hole Admin Interface before 6.3 lets unauthenticated remote attackers inject CRLF sequence

CVE-2020-14162 HIGH POC
7.8 Jul 30

An issue was discovered in Pi-Hole through 5.0. Rated high severity (CVSS 7.8), this vulnerability is low attack complex

CVE-2020-12620 HIGH POC
7.8 Jul 30

Pi-hole 4.4 allows a user able to write to /etc/pihole/dns-servers.conf to escalate privileges through command injection

CVE-2024-44069 HIGH POC
7.5 Aug 19

Pi-hole before 6 allows unauthenticated admin/api.php?setTempUnit= calls to change the temperature units of the web dash

CVE-2021-3706 HIGH POC
7.5 Sep 15

adminlte is vulnerable to Sensitive Cookie Without 'HttpOnly' Flag. Rated high severity (CVSS 7.5), this vulnerability i

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy