LG N1A1 NAS Remote Command Execution Vulnerability (CVE-2018-14839)
Published In CISA KEV since Sources: CVE.org
What is affected, what to do
An attacker can achieve full control over LG N1A1 NAS 3718.510 via a remote code execution vulnerability by sending HTTP POST requests with specific parameters. This vulnerability is actively exploited in ransomware campaigns since 2022. All instances of firmware version 3718.510 are affected. Immediate updating to the latest available firmware version is crucial to mitigate this security risk.
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
- LG N1A1 Firmware
eq 3718.510..3718.510
- LG N1A1 Firmware
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Metrics
9.8
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
9.8
CVSS v3
Severity Critical on the scale from 0 to 10.
Source: CVE.org
89.3 %
EPSS score
High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
Source: FIRST EPSS, percentile 99.78
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- 228.65 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.
Read in glossary- 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.
Read in glossary- 9.8 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- 9.8
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“.
Read in glossary- 89.3 %
- 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- 99.78
- 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.
Read in glossary- 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 · 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 flaw is network-reachable without authentication or user interaction, and a single crafted HTTP POST yields full device takeover. It sits among the CVEs most likely to be exploited at all, driven largely by automated IoT botnet scanning. CISA does not flag ransomware use, but a compromised NAS directly exposes the confidentiality and integrity of the stored data and gives attackers a foothold inside the LAN. Score any internet-exposed unit as critical and act now. For internal-only units, replacement is still high priority, because sustained vendor maintenance for this SoHo-class device is unrealistic.
Runbook step 1
Immediate response (0-24 h)
- Find every unit: Inventory all LG N1A1 NAS devices on firmware 3718.510 using CMDB, DHCP leases, the LG Electronics MAC OUI, or an Nmap HTTP-title sweep on TCP 80/443. Include shadow-IT boxes in branch offices and labs.
- Kill internet exposure now: Remove any port forwards, UPnP mappings or DMZ rules that publish the web UI (TCP 80/443 or custom admin ports). Verify with Shodan/Censys or an external scan of your own public ranges.
- Confirm patch status: The context lists no fixed release. Patch availability must be checked with the vendor — look up the version in the vendor advisory. If no update exists, classify the device as unsupported and start decommissioning.
- Assume compromise if exposed: Any unit that was ever internet-reachable should be treated as compromised. Disconnect it, copy data off via a clean host, and check the data for tampering or encryption.
- Rotate credentials: Change the NAS admin password and every account stored on it (SMB/FTP users, sync and backup targets, cloud tokens), especially where those credentials are reused elsewhere.
Runbook step 2
Mitigation layers
- Network segmentation: Move the NAS into an isolated storage VLAN. Allow the management UI only from an admin jump-host subnet, and allow file shares (SMB TCP 445) only from the client subnets that need them.
- Egress filtering: Apply default-deny outbound internet access for the NAS, with narrow exceptions such as NTP. This breaks payload retrieval (wget/curl/tftp) and C2 callbacks after a successful injection.
- Reverse proxy / IPS rule: If the UI must stay up, front it with a reverse proxy or WAF. Block POST requests to the NAS PHP endpoints whose body contains shell metacharacters (
;,|,`,$(,&&) or strings such aswget,curl,tftp,busybox,/tmp/. Enforce Basic auth or mTLS at the proxy. - Attack-surface reduction: Disable unused services on the device, including UPnP, remote/cloud access, FTP and media server.
- Replacement plan: Treat the unit as legacy IoT and migrate to a supported storage platform. Until then, document a formal risk acceptance aligned with ISO 27001 and NIS2 risk-management obligations.
Runbook step 3
Detection rules
- Zeek
http.log: Flag POST requests to the NAS IP that carry shell metacharacters or downloader commands in the URI or body. Example SPL:index=zeek sourcetype=zeek_http dest_ip=<NAS_IP> method=POST | regex _raw="(;|\||\$\(|)\s*(wget|curl|tftp|sh|busybox|nc)"` - Suricata/IDS: Enable the ET EXPLOIT and ET WEB_SPECIFIC_APPS categories covering LG NAS command injection. Add a custom rule:
alert http any any -> $NAS_NET any (msg:"LG NAS cmd injection attempt"; http.method; content:"POST"; http.request_body; pcre:"/(;|\x60|\$\(|\|)\s*(wget|curl|tftp|sh)/i"; sid:9001483;) - NAS-initiated outbound traffic: Treat any internet-bound connection originating from the NAS (firewall/NetFlow logs) as a high-severity alert. Pay particular attention to HTTP downloads of ELF binaries (Zeek
files.logwithmime_type=application/x-executable), IRC/telnet-style sessions and unusual ports. - Propagation behaviour: A sudden fan-out from the NAS to many hosts on TCP 23, 80 and 8080 indicates botnet spreading. A simple threshold on firewall or Zeek
conn.logdata catches it (for example, more than 100 distinct destination IPs within 5 minutes). - Device logs (if exportable): Watch web-server or syslog entries for malformed or unknown POST requests, and for new processes or files in
/tmp. These devices typically have no EDR, so network visibility is the primary detection layer.
- Zeek
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
LG N1A1 NAS 3718.510 is affected by: Remote Command Execution. The impact is: execute arbitrary code (remote). The attack vector is: HTTP POST with parameters.
Source: NVD (NIST), cvelistv5, CISA KEV Catalog
Vendors and products
Affected operating systems
| Other | lg | n1a1_firmware | 3718.510 |
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.
| CISA KEV Catalog | CISA Known Exploited Vulnerability (opens in a new tab)cisa.gov | actively exploited |
References & sources
- medium.com@0x616163/lg-n1a1-unauthenticated-remote-command-injection-cve-…x_refsource_MISC, Exploit, Third-party advisory
- cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2018-14839government-resource, US government resource
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<a href="https://intel.neosec.eu/en/cve/CVE-2018-14839"><img src="https://intel.neosec.eu/badge/cve/CVE-2018-14839.svg?lang=en" alt="CVE-2018-14839 – NEOSEC Intel" height="20"></a>