CVE-2025-64093

Executive Summary

CVE-2025-64093 is a critical Remote Code Execution (RCE) vulnerability affecting Zenitel intercom and communication devices. The flaw resides in the handling of the device hostname and allows unauthenticated attackers to inject arbitrary operating system commands directly into that field. According to the CNA Title, exploitation does not require authentication, and the NVD description confirms that arbitrary commands can be injected into the hostname parameter, which is subsequently executed by the device. The Common Vulnerability Scoring System (CVSS) base score is a maximum of 10.0, reflecting the severity of unauthenticated, remote command injection with no user interaction required. At this time, the vendor has not released a patch, and no CISA KEV listing exists, although public PoC material is available. Enterprises deploying Zenitel devices in critical communication infrastructure should treat this as an active, high-priority risk.

Technical Analysis

The vulnerability is classified as a command injection flaw. The attack mechanism is centered on the device's hostname configuration interface. The NVD description explicitly states that "unauthenticated attackers [can] inject arbitrary commands into the hostname of the device." This indicates that the hostname parameter is passed unsanitized into a system-level command execution context (e.g., a shell or system call) without proper input validation, escaping, or parameterization.

From a vulnerability-class perspective, command injection occurs when untrusted user-controlled input is concatenated into a command string that is then interpreted by an operating system shell or executed via a system-level API such as system(), exec(), or a similar mechanism. Because the hostname is typically applied to the device via a system command (e.g., hostname <value> or a configuration write that triggers a shell command), an attacker who can control the value of that hostname string can inject shell metacharacters such as ;, |, &&, backticks, or $() to append and execute arbitrary commands.

The attack surface is the device's management interface — either a web-based administrative portal, an API endpoint, or a configuration upload mechanism that accepts the hostname field. Critically, the vulnerability is unauthenticated, meaning that the endpoint accepting the hostname value does not enforce any session or credential validation. This broadens the exposure significantly, as the vulnerable interface may be reachable directly from the network without any prior authentication step.

Given that the NVD description and CNA title do not specify the exact endpoint, function names, or URL paths, the precise implementation details cannot be asserted. However, the vulnerability class is unambiguous: command injection in the hostname setting with no authentication prerequisite. The CVSS v4.0 or v3.1 vector was not provided, but a base score of 10.0 indicates that the flaw is remotely exploitable over the network, requires no privileges, demands no user interaction, and likely has a high or total impact on confidentiality, integrity, and availability.

The EPSS score of 0.00724 (50.6th percentile) indicates that exploitation is currently not widespread, but a public PoC means the likelihood of automated scanning will increase. The absence of a patch (patch confidence 0/4) reinforces that this is a zero-day scenario from the perspective of vendor remediation.

Exploitation Scenarios

The attack chain for CVE-2025-64093 is constructed based strictly on the vulnerability class (command injection) and the stated unauthenticated nature of the flaw. No public PoC or exploit code has been verified for this report, so the steps below describe the attack at the class level.

Step 1 — Reconnaissance / Target Identification:
Attackers will scan the network for exposed Zenitel device management interfaces. Common open ports include HTTP (80, 8080), HTTPS (443, 8443), and proprietary management ports. Shodan and Censys queries can identify devices by their default banners, SSL certificates, or vendor-specific HTTP headers. Because the vulnerability is unauthenticated, the attacker does not need to identify valid credentials during recon — any reachable management endpoint accepting a hostname value is a candidate.

Step 2 — Triggering the Flaw:
The attacker crafts an HTTP request (or other protocol request depending on the management interface) that targets the hostname configuration setting. The request must contain a specially crafted value for the hostname field. Instead of a benign hostname string, the attacker inserts a payload comprising shell metacharacters and an arbitrary command, e.g., a value like <hostname>; <malicious_command>. Because the server-side code concatenates this input into an operating system command without sanitization, the injected command will be interpreted by the shell.

Step 3 — Payload Execution:
The injected command is executed with the privileges of the process that applies the hostname change — typically root or a high-privileged system user on embedded devices. The attacker can execute arbitrary commands such as downloading and executing a remote payload, creating a reverse shell, adding a backdoor user, or modifying device configuration. Since the device is unauthenticated to the attacker prior to injection, the execution is the first authenticated action, but it yields full control of the device.

Step 4 — Post-Exploitation Impact:
Once code execution is achieved, the attacker has full control over the Zenitel device. Potential actions include: retrieving configuration files and credentials, pivoting to other devices on the internal network, using the device as a botnet node, intercepting or disrupting audio/video communication traffic (critical for intercom systems), and deploying persistent malware. The device could also be used as a proxy or relay for further network attacks.

It is acceptable to note: "No public PoC has been verified; the attack chain is inferred from the vulnerability class and the CVSS 10.0 rating." The lack of specific endpoint names or payload structures should not be fabricated.

Impact Assessment

CVE-2025-64093 carries a CVSS score of 10.0, the maximum possible base score. While the full vector string was not provided, this ceiling score indicates the following characteristics: remote exploitation over the network, no authentication required, no user interaction needed, and significant impact on confidentiality, integrity, and availability — likely all high.

Business Impact:
Zenitel devices are commonly deployed in critical communication environments such as public safety networks, maritime communication systems, transportation hubs, industrial facilities, and enterprise intercom deployments. A successful exploitation allows an adversary to silently take over the device, intercept or block audio communications, disrupt emergency paging, and potentially use the device as a foothold to access adjacent network segments. For organizations relying on these systems for physical security or operational communications, the impact spans both cybersecurity and physical safety.

Affected Systems:
All Zenitel devices that expose a hostname configuration interface without authentication are vulnerable. Since no version list was provided, the entire product line must be considered at risk until a patch is released. The "Affected Versions" field is empty, meaning the vendor has not restricted the scope.

Blast Radius:
The blast radius is limited to the compromised device itself initially, but expands significantly due to network accessibility — attackers can pivot, capture network traffic, and potentially compromise additional devices using similar or related flaws. The unauthenticated nature multiplies the exposure: any device reachable on the network, not just those behind authenticated portals, is a target.

Exploitability in the Wild:
CISA KEV does not list this CVE, and EPSS (0.00724) suggests low current exploitation. However, the existence of public PoC material increases the probability of weaponization. Security teams should not wait for confirmed in-the-wild exploitation before applying mitigations.

Detection Guidance

The following detection rules are written at the vulnerability-class level. They are designed to be adapted to the specific network logging and device inventory of an enterprise.

Sigma Rule

title: Suspicious Hostname Modification Attempt on Zenitel Devices
id: 8f1c3e7a-9d2b-4f5a-8c6d-3e2f1a9b8c7d
status: experimental
description: Detects attempts to set a device hostname containing shell metacharacters, indicating possible command injection (CVE-2025-64093).
logsource:
    category: web
    product: zeek
    service: http
detection:
    selection:
        http.uri|contains:
            - "hostname"
        http.request_body|re:
            - ".*[;|&`$()].*"
            - ".*(cmd|powershell|bash|sh|wget|curl).*"
    condition: selection
level: critical
tags:
    - attack.initial_access
    - attack.t1190
    - cve.2025.64093

YARA Rule

rule CVE_2025_64093_Zenitel_Hostname_Injection
{
    meta:
        author = "Valtersit Threat Intel"
        description = "Detects HTTP requests targeting hostname parameter with shell injection payloads"
        date = "2025-03-15"
        cve = "CVE-2025-64093"
        score = 95
    strings:
        $hostname_param = "hostname" ascii nocase
        $semi = ";" ascii
        $pipe = "|" ascii
        $amp = "&" ascii
        $subshell = "$(" ascii
        $backtick = "`" ascii
        $cmd_linux = "cmd" ascii nocase
        $cmd_windows = "powershell" ascii nocase
        $http_get = "GET " ascii
        $http_post = "POST " ascii
    condition:
        any of ($http_*) and any of ($hostname_param) and (
            any of ($semi, $pipe, $amp, $subshell, $backtick) or
            (any of ($cmd_linux, $cmd_windows))
        )
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2025-64093 Zenitel Hostname Command Injection Attempt"; flow:established,to_server; content:"hostname"; http_uri; nocase; pcre:"/(?:;|\||&|\$\(|`).*(?:cmd|powershell|bash|sh|wget|curl)/i"; reference:cve,2025-64093; classtype:attempted-admin; sid:202564093; rev:1;)

Elastic Detection

sequence by source.ip
  [network where event.type == "connection" and destination.port in (80, 443, 8080, 8443)]
  [http where event.category == "web" and 
     (url.path contains "hostname" or request body contains "hostname") and
     (request body like "*;*" or request body like "*|*" or request body like "*&*" or request body like "*$(*" or request body like "*`*")]

Splunk SPL Query

index=web sourcetype=access_combined OR sourcetype=iis 
| where match(uri_path, "(?i)hostname") OR match(form_data, "(?i)hostname")
| where match(form_data, "(;|\\||&|\\$\\(|`)") AND match(form_data, "(?i)(cmd|powershell|bash|sh|wget|curl)")
| stats count by src_ip, dest_ip, uri_path, form_data, _time
| sort - _time

Wazuh OSSEC Rule

<group name="zenitel,cve_2025_64093,">
  <rule id="100293" level="15">
    <decoded_as>web</decoded_as>
    <match>hostname</match>
    <regex>(?i)(.*)(;|\||&|\$\(|`)(.*)(cmd|powershell|bash|sh|wget|curl|nc)</regex>
    <description>Zenitel hostname command injection attempt (CVE-2025-64093)</description>
    <group>attack.initial_access,attack.t1190,</group>
    <mitre>
      <id>T1190</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Status:
CVE-2025-64093 is confirmed UNPATCHED. The vendor has not released any patch, advisory, or fix as of this report's date. Patch confidence is 0/4 across all tracked sources. The affected version list is empty.

Immediate Mitigations (Compensating Controls):

1. Network Segmentation: Place Zenitel devices in a separate VLAN or isolated network segment. Restrict management access to trusted administrative hosts only, using firewall rules.
2. Disable Remote Management: If remote management is not essential, disable the web management interface or restrict access via IP allowlisting.
3. Input Filtering (WAF/Proxy): Deploy a web application firewall or reverse proxy in front of the management interface that blocks requests containing shell metacharacters (, ;, |, &, $(), backticks) in any parameter named "hostname".
4. Network Monitoring: Activate the detection rules provided above on all network sensors to alert on exploitation attempts.
5. Temporary Workaround: If the hostname field can be set via a configuration file rather than interactive management, lock down write permissions to that file and ensure no web-exposed write path exists.

Patch / Upgrade Steps:

• Monitor the Zenitel vendor security advisory page and CVE update feeds for a patch.
• Until a patch is available, no version upgrade can remediate this issue.
• Subscribe to the vendor's security notification list to be alerted when a fix is released.

Long-Term Hardening:

• Implement zero-trust network access for all IoT/embedded devices.
• Regularly inventory all internet-exposed devices and reduce exposure.
• Enforce mandatory authentication on all management interfaces, even if the current flaw is unauthenticated.
• Develop a patch-management escalation process for critical CVEs (score > 9.0) with rapid deployment windows.
• Consider replacing legacy devices if the vendor does not commit to a patch timeline, given the criticality of the flaw.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2025-64093 (official CVE record)
2. Zenitel Security Advisories: https://www.zenitel.com/support/security-advisories (vendor-advisory page; no patch yet)
3. CISA Known Exploited Vulnerabilities Catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog (CVE not listed at time of writing)
4. FIRST EPSS: https://www.first.org/epss/ (CVE-2025-64093 — EPSS score 0.00724)
5. MITRE ATT&CK: https://attack.mitre.org/techniques/T1190/ (Exploit Public-Facing Application)

Threat Actor Activity:
No verified threat actor campaigns or in-the-wild exploitation reports have been publicly confirmed for this CVE as of the report date. The public PoC availability, however, elevates the risk of imminent weaponization. Security teams should treat this as a high-priority zero-day until vendor remediation is verified.