CVE-2026-18813 Overview
CVE-2026-18813 is a command injection vulnerability affecting H3C NX15 V100R017. The flaw resides in the delete function of the /api/esps endpoint. Attackers can manipulate the esps.apcm.version argument to inject operating system commands. The vulnerability is exploitable remotely and requires high-privilege authentication. Public disclosure of the exploit has occurred, increasing the risk of opportunistic attacks against exposed devices. The weakness maps to [CWE-74] Improper Neutralization of Special Elements in Output Used by a Downstream Component (Injection).
Critical Impact
Successful exploitation allows remote command execution against the underlying operating system through the H3C NX15 web API, compromising device confidentiality, integrity, and availability.
Affected Products
- H3C NX15 running firmware version V100R017
- The /api/esps API endpoint (delete operation)
- Deployments exposing the H3C management API to untrusted networks
Discovery Timeline
- 2026-08-04 - CVE-2026-18813 published to NVD
- 2026-08-05 - Last updated in NVD database
Technical Details for CVE-2026-18813
Vulnerability Analysis
The vulnerability exists in the delete handler of the /api/esps endpoint on the H3C NX15 device. The handler accepts an esps.apcm.version parameter that is passed to a shell or system-level command without adequate sanitization. Attackers who can authenticate with elevated privileges can append shell metacharacters to inject arbitrary commands. Public references indicate the outcome is root-level remote code execution on the device. Because the API is reachable over the network, exposed management interfaces materially increase exposure.
Root Cause
The root cause is improper neutralization of special elements passed to a downstream system command, classified as [CWE-74]. The application concatenates untrusted input from esps.apcm.version into a command string rather than using safe argument passing or strict allow-list validation. This is a classic command injection pattern common in embedded network devices where web UI handlers invoke shell utilities.
Attack Vector
The attack vector is network based. An authenticated attacker sends a crafted HTTP request to /api/esps invoking the delete operation with a malicious esps.apcm.version value. Shell metacharacters such as ;, |, `, or $() allow the attacker to break out of the intended command and execute arbitrary payloads. A public proof of concept is available in the IOT_Vul_Public GitHub repository.
No verified exploitation code is reproduced here. Refer to the VulDB Vulnerability Details entry for additional technical context.
Detection Methods for CVE-2026-18813
Indicators of Compromise
- HTTP requests to /api/esps containing shell metacharacters (;, |, &, `, $() inside the esps.apcm.version parameter
- Unexpected child processes spawned by the H3C web management daemon
- Outbound connections from the device to unfamiliar hosts following API calls
- New or modified files in device-writable paths shortly after /api/esps delete calls
Detection Strategies
- Inspect web access logs on the H3C NX15 for DELETE or delete-action requests targeting /api/esps with anomalous esps.apcm.version values
- Deploy network intrusion detection signatures that flag shell metacharacters in H3C management API parameters
- Correlate authentication events with subsequent API calls to detect misuse of high-privilege credentials
Monitoring Recommendations
- Forward device syslog and web management logs to a centralized SIEM for long-term retention and correlation
- Baseline normal administrative activity against /api/esps and alert on deviations in request frequency or payload structure
- Monitor egress traffic from network appliances for reverse shell patterns and unexpected outbound sessions
How to Mitigate CVE-2026-18813
Immediate Actions Required
- Restrict access to the H3C NX15 management interface to trusted administrative networks only, using ACLs or firewall rules
- Rotate credentials for all high-privilege accounts capable of invoking /api/esps
- Audit recent web management logs for signs of exploitation of the esps.apcm.version parameter
- Contact H3C support to confirm patch availability for NX15 V100R017 and schedule remediation
Patch Information
At the time of publication, no vendor advisory URL for a fixed firmware release is listed in the NVD entry. VulDB indicates the vendor was contacted prior to disclosure. Consult the VulDB CVE Entry and H3C support channels for updated firmware for NX15 V100R017.
Workarounds
- Block external access to /api/esps at the perimeter until a vendor patch is applied
- Place the device management plane on an isolated out-of-band network segment
- Enforce multi-factor authentication and principle-of-least-privilege for administrative accounts
- Disable or remove unused administrative accounts that could be leveraged to reach the vulnerable endpoint
# Example: restrict /api/esps access to a trusted management subnet using an upstream firewall
# Replace 10.10.10.0/24 with your actual management network
iptables -A FORWARD -p tcp -s 10.10.10.0/24 -d <h3c_nx15_ip> --dport 443 -j ACCEPT
iptables -A FORWARD -p tcp -d <h3c_nx15_ip> --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
