CVE-2025-34087 in Web
Summary
by MITRE • 07/03/2025
An authenticated command injection vulnerability exists in Pi-hole versions up to 3.3. When adding a domain to the allowlist via the web interface, the domain parameter is not properly sanitized, allowing an attacker to append OS commands to the domain string. These commands are executed on the underlying operating system with the privileges of the Pi-hole service user.
This behavior was present in the legacy AdminLTE interface and has since been patched in later versions.
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Analysis
by VulDB Data Team • 07/04/2025
The vulnerability identified as CVE-2025-34087 represents a critical authenticated command injection flaw within the Pi-hole network-level ad blocking software. This issue affects versions up to 3.3 and specifically targets the allowlist management functionality through the web interface. The vulnerability stems from insufficient input validation and sanitization of user-supplied domain parameters, creating a pathway for malicious command execution within the system's operating environment. The flaw exists within the legacy AdminLTE interface implementation, which has since been addressed in subsequent releases, highlighting the importance of timely security updates in maintaining system integrity.
The technical exploitation of this vulnerability occurs when an authenticated user interacts with the allowlist feature through the web administration panel. When adding a domain to the allowlist, the system fails to properly sanitize the domain parameter input, allowing specially crafted malicious input to bypass validation mechanisms. This vulnerability directly maps to CWE-77, which describes improper neutralization of special elements used in a command, and CWE-94, which covers execution of arbitrary code/commands. The injection occurs because the application directly incorporates user-supplied input into system commands without proper escaping or filtering, creating a classic command injection vector. The underlying operating system executes these commands with the privileges of the Pi-hole service user, potentially providing attackers with elevated access to the network infrastructure.
The operational impact of this vulnerability extends beyond simple command execution, as it can enable attackers to compromise the entire Pi-hole system and potentially the broader network infrastructure it protects. An attacker with valid administrative credentials can leverage this vulnerability to execute arbitrary system commands, potentially leading to data exfiltration, system modification, or even complete system compromise. The implications are particularly concerning given that Pi-hole serves as a network-level ad blocker and DNS sinkhole, making it a critical component in network security infrastructure. The vulnerability's presence in the legacy AdminLTE interface suggests that organizations relying on older Pi-hole versions may be exposed to persistent risks, as the patch was implemented in later releases but not backported to older versions.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected Pi-hole installations to version 3.4 or later, where the command injection flaw has been addressed. Organizations should also implement network segmentation and access controls to limit administrative access to Pi-hole interfaces, reducing the attack surface. The principle of least privilege should be enforced by ensuring that the Pi-hole service operates with minimal required permissions and that administrative access is restricted to authorized personnel only. Security monitoring should include detection of unusual command execution patterns and unauthorized access attempts to the Pi-hole administration interface. Additionally, regular security audits and vulnerability assessments should be conducted to identify similar issues in other network infrastructure components, following ATT&CK framework guidance for command and control activities and privilege escalation techniques.