CVE-2026-79803

Executive Summary

CVE-2026-79803 is a command injection vulnerability (CWE-78) affecting the API of ClearPass Policy Manager, Aruba's network access control (NAC) platform. An authenticated remote attacker with low privileges can inject arbitrary operating system commands through the API, escalating privileges and gaining full administrative control of the affected system. No public proof-of-concept, exploit code, or vendor patch is currently available, making this a significant unpatched risk for organizations relying on ClearPass for network authentication and policy enforcement.

Technical Analysis

The vulnerability resides in the API layer of ClearPass Policy Manager. Command injection (CWE-78) occurs when untrusted input is passed to a system shell or command execution function without adequate sanitization or escaping. In this case, the NVD description confirms that the flaw is reachable through the product's API and is exploitable by an authenticated remote attacker.

The CVSS vector (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) indicates:

• Attack Vector (Network): The API is reachable over the network, consistent with ClearPass being a centrally deployed NAC appliance.
• Attack Complexity (Low): No special conditions or race conditions are required — the injection is straightforward once API access is obtained.
• Privileges Required (Low): The attacker must be authenticated, but only with a low-privileged account. This substantially lowers the bar, as ClearPass environments often include guest, operator, or service accounts.
• User Interaction (None): No victim action is needed.
• Scope (Unchanged): The exploit remains within the security authority of the vulnerable component.
• Confidentiality/Integrity/Availability (High): Successful exploitation yields administrative control, implying full read/write/execute over the system and its data.

Because the API is the attack surface, the injection point is likely a parameter processed by a backend command execution routine — a common pattern in management appliances where API handlers shell out to system utilities for tasks such as diagnostics, network configuration, or service management. However, no specific function names, API endpoints, or parameters are disclosed in the available data, so the exact injection sink cannot be confirmed. The vulnerability class is unambiguous: unsanitized user-controlled input reaching a command interpreter.

Exploitation requires the attacker to first obtain valid credentials for the API. This could be achieved through credential stuffing, default credentials, phishing, or prior compromise of a lower-privileged account. Once authenticated, the attacker can craft API requests containing shell metacharacters (e.g., ;, |, &&, backticks, $()) that the backend fails to neutralize, resulting in arbitrary command execution under the privileges of the API service — likely root or a highly privileged service account on the ClearPass appliance.

Exploitation Scenarios

No public PoC is available; the attack chain below is inferred from the vulnerability class (command injection) and the NVD description. No specific API endpoints, parameter names, or function names are invented.

1. Reconnaissance / Target Identification An attacker identifies an internet-facing or internally reachable ClearPass Policy Manager instance. ClearPass is typically deployed as a NAC policy engine, so exposure may be limited to management networks, but misconfigurations or VPN access can broaden reachability. The attacker enumerates the API surface and identifies endpoints that accept user-supplied input likely to be processed by the underlying OS (e.g., diagnostic, logging, or configuration functions). Without a published advisory, the exact endpoint must be discovered through manual testing or fuzzing.

2. Authentication and Privilege Acquisition The attacker obtains valid low-privileged credentials. This could be via default accounts, credential reuse, leaked secrets, or a separate initial-access vector. Because the CVSS vector specifies PR:L, only a basic authenticated session is required — no administrative role is needed to reach the vulnerable code path.

3. Triggering the Command Injection The attacker sends a crafted API request that includes shell metacharacters within a parameter that is passed to a system command. For example, a value such as valid_input; arbitrary_command or valid_input| arbitrary_command would, if unsanitized, cause the backend to execute the injected command. The specific parameter and endpoint are not disclosed in the available data; the injection class is command injection (CWE-78), and the mechanism is failure to sanitize or escape input before shell execution.

4. Post-Exploitation Impact Successful command injection executes commands with the privileges of the API service, which on a NAC appliance is typically root or an equivalent high-privilege account. The attacker can then escalate to full administrative control: create admin users, modify authentication policies, exfiltrate credential stores and network configuration, pivot to other managed devices, or install persistent backdoors. Given ClearPass's role in network access control, compromise can lead to lateral movement across the entire managed network estate.

Impact Assessment

The CVSS base score of 8.8 (High) reflects high confidentiality, integrity, and availability impact. A compromised ClearPass Policy Manager is a high-value target: it is the trust anchor for network authentication, authorization, and accounting (AAA). Administrative control allows an attacker to:

• Bypass or weaken 802.1X, MAC authentication, and role-based access controls.
• Extract credentials, certificates, and secrets used for network device integration.
• Modify or disable policies, granting unauthorized devices network access.
• Use the appliance as a pivot point into segmented networks.

The blast radius extends beyond the appliance itself: all downstream network devices, endpoints, and users relying on ClearPass for access decisions are potentially affected. Because the vulnerability requires authentication (PR:L), the immediate risk is lower than an unauthenticated RCE, but the prevalence of shared or weakly protected service accounts in NAC deployments elevates the practical threat. EPSS is not yet scored by FIRST.org, so no probabilistic exploitation forecast is available. CISA KEV does not list this CVE, and no public exploit code or Nuclei template exists, indicating the vulnerability is not yet weaponized in the wild — but the absence of a patch (0/4 confidence) means defenders cannot rely on vendor remediation.

Detection Guidance

Sigma Rule

title: Command Injection Attempt Against ClearPass Policy Manager API
id: 8f2c1a4e-9b3d-4e7a-9c1f-2d6e8a0b5f3c
status: experimental
description: Detects shell metacharacters in HTTP requests to ClearPass Policy Manager API endpoints, indicative of command injection attempts.
references:
  - https://nvd.nist.gov/vuln/detail/CVE-2026-79803
author: valtersit.com
date: 2026-01-01
tags:
  - attack.t1190
  - attack.execution
logsource:
  category: webserver
  product: aruba
detection:
  selection_method:
    cs-method:
      - 'POST'
      - 'GET'
      - 'PUT'
  selection_uri:
    cs-uri-stem|contains:
      - '/api/'
  selection_payload:
    cs-uri-query|contains:
      - ';'
      - '|'
      - '&&'
      - '$(', '`'
      - '>'
  condition: selection_method and selection_uri and selection_payload
falsepositives:
  - Legitimate API calls containing encoded characters in parameters
level: high

YARA Rule

rule CVE_2026_79803_ClearPass_CommandInjection
{
    meta:
        description = "Detects command injection payloads targeting ClearPass Policy Manager API"
        author = "valtersit.com"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2026-79803"
        date = "2026-01-01"
        severity = "high"

    strings:
        $api = "/api/" ascii nocase
        $semicolon = ";" ascii
        $pipe = "|" ascii
        $amp = "&&" ascii
        $subshell = "$(" ascii
        $backtick = "`" ascii
        $clearpass = "ClearPass" ascii nocase

    condition:
        $clearpass and $api and 1 of ($semicolon, $pipe, $amp, $subshell, $backtick)
}

Suricata IDS Rule

alert http any any -> any any (msg:"CVE-2026-79803 ClearPass Policy Manager API Command Injection Attempt"; flow:to_server,established; http.uri; content:"/api/"; http.uri; pcre:"/(;|\||&&|\$\(|`)/U"; classtype:attempted-admin; sid:202679803; rev:1; metadata:created_at 2026_01_01, updated_at 2026_01_01, cve CVE-2026-79803;)

Elastic Detection

sequence by source.ip with maxspan=5s
  [network where event.action == "network_flow" and url.path : "/api/*"]
  [network where event.action == "network_flow" and url.query : ("*;*" or "*|*" or "*&&*" or "*$(*" or "*`*")]

Splunk SPL Query

index=web OR index=proxy
| search (uri_path="/api/*" OR url="*/api/*")
| where match(url, "(;|\||&&|\$\(|`)")
| stats count min(_time) as first_seen max(_time) as last_seen by src_ip, dest_ip, url, http_method
| where count > 0
| sort - count

Wazuh OSSEC Rule

<group name="clearpass,web,attack,">
  <rule id="100803" level="12">
    <decoded_as>web-accesslog</decoded_as>
    <field name="url">/api/</field>
    <regex field="url">(;|\||&&|\$\(|`)</regex>
    <description>CVE-2026-79803: Possible command injection attempt against ClearPass Policy Manager API</description>
    <mitre>
      <id>T1190</id>
    </mitre>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence is 0/4: no patch evidence exists from any tracked source, no vendor fix is documented, and no workaround is published.

1) Immediate mitigations

• Restrict network access to the ClearPass API to trusted management networks and administrative hosts only; never expose the API to the internet.
• Enforce the principle of least privilege for API accounts; audit and remove unused or over-privileged service accounts.
• Enable strong authentication (MFA where supported) and monitor for anomalous authenticated API activity.
• Deploy virtual patching via WAF/IPS rules targeting shell metacharacters in API requests (see detection rules above).
• Segment the ClearPass appliance from the general network to limit lateral movement if compromised.

2) Patch / upgrade steps

• Monitor Aruba/HPE security advisories for CVE-2026-79803 for an official fix. No patch is currently available.
• When a patch is released, test in a staging environment before production rollout, and verify the patch addresses the API command injection path.
• Until patched, treat the appliance as a high-risk asset and apply compensating controls.

3) Long-term hardening

• Implement input validation and output encoding across all API handlers that invoke system commands; avoid shell invocation entirely where possible.
• Adopt secure coding standards (OWASP ASVS) for API development.
• Conduct regular penetration testing and fuzzing of the API surface.
• Integrate threat intelligence feeds and monitor for exploitation attempts against NAC infrastructure.
• Maintain an asset inventory of all ClearPass deployments and ensure they are included in vulnerability management programs.

References

• NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-79803
• HPE Aruba Networking Security Advisories: https://www.arubanetworks.com/support-services/security-bulletins/
• CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'): https://cwe.mitre.org/data/definitions/78.html
• FIRST EPSS: https://www.first.org/epss/ (CVE-2026-79803 not yet scored)
• CISA Known Exploited Vulnerabilities Catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog (CVE-2026-79803 not listed)

No known threat actor campaigns or exploit-in-the-wild evidence are available for this CVE at this time.