CriticalCVE-2020-8816

    Pi-Hole AdminLTE Remote Code Execution Vulnerability (CVE-2020-8816)

    Published In CISA KEV since Sources: CVE.org

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    What is affected, what to do

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

    The vulnerability is being actively exploited; treat it as a priority. The available sources name no fixed version. Check the vendor guidance in the references below. Immediate actions, mitigation and detection rules are in the runbook below.

    Affected
    • Pi-hole AdminLTE lte *..4.3.2

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    9.1

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    9.1

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: CVE.org

    78.3 %

    EPSS score

    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.

    Source: FIRST EPSS, percentile 99.58

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    224.83 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

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    actively exploited
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

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    9.1 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    9.1
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

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    78.3 %
    High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    99.58
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

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    Actively exploited
    Published
    In CISA KEV since

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    CISA assessment (SSVC)
    Exploitation: active · not automatable · Technical impact: total
    Source: CISA Vulnrichment, as of 4 February 2025
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-78

    Response and mitigation

    Why act now?

    Prioritisation rationale

    The attacker needs an authenticated admin session first, which lowers raw internet exposure — but CISA added this CVE to KEV because Pi-hole instances in home-lab and small-office networks are routinely exposed with default or weak passwords and then abused as a pivot into internal networks. The CVSS vector reflects network-based exploitation with full host compromise, and exploitation likelihood is very high because public PoCs exist. Treat this as high priority wherever Pi-hole serves DHCP in production or where the admin UI is reachable outside a management segment; a pure DNS-sinkhole deployment with no DHCP role and tightly segmented admin access can be patched within the normal maintenance window.

    1. Runbook step 1

      Immediate response (0-24 h)

      • Upgrade Pi-hole AdminLTE beyond 4.3.2 via pihole -up; the vulnerable release is 4.3.2 and earlier.
      • Remove the admin dashboard from the internet: TCP/80 and TCP/443 on the Pi-hole host must not be WAN-reachable. Audit and remove any port-forwards, reverse-proxy exposures or UPnP mappings pointing at the Pi-hole box.
      • Rotate the admin password with pihole -a -p; treat as credential compromise if the password was shared or stored outside a vault, including SSH keys and API tokens from /etc/pihole/setupVars.conf.
      • Disable Pi-hole's DHCP server function temporarily if not strictly required (Settings > DHCP > Disable); the exploit path runs through the DHCP static-lease configuration page.
      • Hunt for compromise: inspect /var/www/html/admin/, /etc/pihole/dhcp.leases and /etc/dnsmasq.d/04-pihole-static-dhcp.conf for unexpected entries, shell metacharacters and anomalous mtimes.

    2. Runbook step 2

      Mitigation layers

      • Network segmentation: move Pi-hole into a management VLAN; restrict access to the web UI via ACL to a defined admin subnet or require VPN/bastion traversal.
      • Reverse proxy hardening: where nginx/Traefik/Caddy fronts the dashboard, enforce Basic-Auth on top of Pi-hole's own auth and rate-limit POSTs to /admin/settings.php.
      • Local hardening: run lighttpd under a least-privileged account; audit /etc/sudoers.d/pihole and strip NOPASSWD rights that let www-data run privileged helpers — RCE escalates through exactly these entries.
      • IAM: eliminate shared admin logins, enforce per-operator accounts, log dashboard activity. If multi-admin is not supported, funnel access through a single auditable account via bastion.
      • WAF/IPS: block POST requests to settings.php whose DHCP fields (AddMAC, AddIP, AddHostname) contain shell metacharacters (;, |, `, $(). Deploy a Suricata/Snort signature matching POST /admin/settings.php plus DHCP plus metacharacters in the request body.

    3. Runbook step 3

      Detection rules

      • Web server log (lighttpd /var/log/lighttpd/access.log): POST to /admin/settings.php with tab=piholedhcp or AddMAC/AddHostname parameters containing shell metacharacters. KQL shape: WebLogs | where UriPath endswith "settings.php" and HttpMethod == "POST" and RequestBody matches regex "(;|\\||\\$\\(|)"`.
      • Process ancestry (auditd / Sysmon-for-Linux EID 1): children of lighttpd or php-cgi spawning sh, bash, nc, curl, wget, python — unusual for a Pi-hole host. Sigma: parent_image: /usr/sbin/lighttpd + image endswith /sh.
      • File integrity on /etc/dnsmasq.d/04-pihole-static-dhcp.conf and /etc/pihole/custom.list: alert on unexpected modifications or entries containing non-MAC/IP characters (auditd -w /etc/dnsmasq.d/ -p wa).
      • Network telemetry: outbound connections from the Pi-hole host to anything other than DNS/NTP endpoints, especially TCP reverse shells to external IPs. Zeek conn.log: id.orig_h == <pihole_ip> and service != "dns" and id.resp_p not in (53, 123, 80, 443).
      • Authentication: unusual successful dashboard logins outside admin working hours; correlate pihole-FTL.log and query log for new API usage patterns.

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

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

    Source: NVD (NIST), cvelistv5, CISA KEV Catalog

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    pi-holepi-hole
    • ≤ 4.3.2
    • —

    Vendors and products

    Weakness classes (CWE)

    • CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

      Base

      The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

      Entry at MITRE CWE-78

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    CISA KEV CatalogCISA Known Exploited Vulnerability (opens in a new tab)cisa.govactively exploited
    Packet StormPi Hole 4.3.2 DHCP MAC OS Command Execution (opens in a new tab)packetstormsecurity.comPoC (publicly reported)reported, not verified—
    Packet StormPi hole 4.3.2 Remote Code Execution (opens in a new tab)packetstormsecurity.comPoC (publicly reported)reported, not verified—

    References & sources

    • github.compi-hole/AdminLTE/commits/masterx_refsource_MISC, Patch, Third-party advisory
    • packetstormsecurity.comfiles/157861/Pi-Hole-4.3.2-DHCP-MAC-OS-Command-Execution.htmlx_refsource_CONFIRM, Third-party advisory, Vulnerability database
    • natedotred.wordpress.com2020/03/28/cve-2020-8816-pi-hole-remote-code-executionx_refsource_MISC, Broken link, Exploit, Third-party advisory
    • twitter.comNate_Kappa/status/1243900213665902592?s=20x_refsource_MISC, Broken link, Press coverage
    • github.compi-hole/AdminLTE/releases/tag/v4.3.3x_refsource_MISC, Release notes, Third-party advisory
    • github.compi-hole/AdminLTE/pull/1165x_refsource_MISC, Patch, Third-party advisory
    • packetstormsecurity.comfiles/158737/Pi-hole-4.3.2-Remote-Code-Execution.htmlx_refsource_MISC, Third-party advisory, Vulnerability database
    • cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2020-8816government-resource, US government resource
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