CVE-2026-73768

Executive Summary

CVE-2026-73768 is a command injection vulnerability in the command line interface (CLI) of HPE ArubaOS-CX network operating system, stemming from improper processing of malformed input (CWE-20). A low-privileged local attacker can exploit this flaw to execute arbitrary commands with root privileges on affected switches, achieving full system compromise. The vulnerability carries a CVSS score of 7.3 (High) and is currently not listed on the CISA KEV, though public PoC material exists. A patch is claimed by a single source (NVD) but remains unconfirmed by independent verification, making verification of patched versions critical before deployment.

Technical Analysis

The vulnerability resides within the command line interface (CLI) parser of AOS-CX — the network operating system for HPE ArubaOS-CX series switches (e.g., CX 6300, CX 8300, CX 10000 series platforms). AOS-CX provides a rich CLI for network administrators to configure routing, switching, security policies, and system-level parameters on network devices.

The root cause is classified under CWE-20 (Improper Input Validation). The CLI parser fails to properly validate or sanitize certain types of malformed input in command arguments. The NVD description states the flaw allows "improper processing of malformed input" resulting in the "execution of arbitrary commands with root privileges."

At a vulnerability-class level, command injection in network device CLIs commonly arises in one of several mechanisms:

1. Argument injection into shell commands: CLI commands that internally invoke shell utilities (e.g., ping, traceroute, copy, or diagnostic functions) concatenate user-supplied arguments with shell metacharacters (e.g., ;, |, &&, backticks) without proper escaping.
2. Configuration value injection: Certain configuration parameters accepted via the CLI are later processed by privileged backend daemons or scripts without adequate validation, allowing values that contain command substitution syntax to be executed.
3. Parser state confusion: Malformed syntax may cause the parser to misinterpret subsequent input blocks as executable command directives, bypassing intended privilege checks.

The CVSS vector reveals important characteristics of the attack: AV:L (Local access required), AC:L (Low attack complexity), PR:L (Low privileges required — authenticated user with basic access rights), UI:R (User interaction required — a user with low privileges must perform an action, e.g., issue a specific command). The impact subscores C:H/I:H/A:H indicate full confidentiality, integrity, and availability compromise upon successful exploitation.

Since the underlying code affected is the CLI parser of AOS-CX, the flaw is deeply embedded in the OS's command-handling logic and likely requires authenticated local CLI access (e.g., an admin with a low-privileged CLI role or SSH session) to trigger.

Electronically, the EPSS score of 0.00122 (2.3% percentile) suggests exploitation in the wild is currently unlikely; however, public PoC availability increases the risk of future weaponization.

Exploitation Scenarios

Attack Chain (inferred from vulnerability class; no public PoC code disclosed):

Step 1 — Reconnaissance / Target Identification: Attackers first identify AOS-CX devices that are reachable and have enabled CLI management interfaces (SSH typically on TCP/22, or the serial console). Enterprise network infrastructure is often logged via Shodan-like scans using product fingerprints. Attackers also attempt to harvest credentials for low-privileged CLI accounts via social engineering, default credential attacks (though not supported by the CVE data), or by compromising a network administrator workstation with lateral movement into the management plane.

Step 2 — Triggering the Flaw: An authenticated attacker with low-privilege CLI access (e.g., a helpdesk account, monitoring account, read-only user, or guest role) interacts with the CLI. The attacker issues a targeted command that accepts user-controlled input (such as an IP address field, hostname parameter, filename argument, or diagnostic command parameter). The attacker crafts a malformed input string that contains shell metacharacters or command substitution syntax, which is not properly validated by the parser. This is the core CWE-20 flaw: the device's parser processes the string without adequate sanitization.

Step 3 — Payload/Execution: The malicious input is passed to a privileged backend process or shell instance running with root privileges. The payload (e.g., $(cmd), ; sh -i, or pipe to a second command) causes the underlying shell to interpret the injected commands with root authority. Public PoC availability suggests at least one craftable payload chain is known, though precise payload syntax is not publicly documented.

Step 4 — Post-Exploitation Impact: Once arbitrary commands execute as root, the attacker gains full control over the switch operating system. Could achieve:

• Reading sensitive configuration files (e.g., SNMP community strings, RADIUS/TACACS+ shared secrets, management credentials, password hashes).
• Installing persistent backdoors (e.g., modifying startup scripts, copying binaries to flash, creating hidden CLI aliases).
• Disabling security controls (e.g., turning off logging, changing default gateway routes to redirect traffic).
• Data exfiltration of network traffic traversing the switch via port mirroring.
• Destructive acts: erasing boot configuration, firmware modifications, denial of service to the switching plane.

Caveat: No public PoC code or exploit write-up was disclosed at the time of this report; attack chain is inferred from the vulnerability class (CWE-20) and the CVSS access vector. Specific command names and payload syntax are not available in public CVE data.

Impact Assessment

Business Impact: AOS-CX switches are deployed as core and access-layer infrastructure in enterprise data centers, campus networks, and industrial environments. Successful exploitation provides root-level access to the management plane, which typically implies:

• Complete network control: An attacker with root on a switch can manipulate forwarding tables, ACLs, VLANs, routing protocols, and potentially inject malicious traffic into the broader network fabric (MITM attacks, traffic redirection, network segmentation bypass).
• Persistence: Infrastructure devices are rarely rebooted or re-imaged. A crafted implant could remain undetected for months.
• Lateral movement: Network devices often serve as jump hosts or hold credentials to other parts of the network.

Blast Radius: Each compromised switch is an island of control, but due to the nature of network architecture, all traffic crossing that switch is compromised. In flat networks, this could expose 100% of east-west traffic. Multi-tier architectures limit this to the specific network segment the switch serves.

Assessment based on CVSS subscores:

• Confidentiality (High): All data traversing the switch and configuration secrets readable.
• Integrity (High): Filters, routes, QoS can be modified; traffic could be silently dropped or redirected.
• Availability (High): An attacker can cause a complete outage by corrupting the firmware, disabling the management plane, or flooding the CPU.

Affected Systems: AOS-CX codebase — specific affected versions list is empty in the CVE data, affecting ambiguity in remediation. Organizations running any version of AOS-CX on HPE Aruba CX switches should treat themselves as potentially affected until patched versions are confirmed.

Detection Guidance

Sigma Rule

title: AOS-CX CLI Command Injection Attempt (CVE-2026-73768)
id: a1b2c3d4-e5f6-7890-abcd-ef1234567890
status: experimental
description: Detects suspicious CLI input patterns on ArubaOS-CX devices potentially exploiting CVE-2026-73768
logsource:
    product: network
    service: aoscx_cli
detection:
    selection:
        event.category: cli
        message|contains:
            - ';'
            - '|'
            - '&&'
            - '`'
            - '$(​)'
            - '> /tmp/'
            - 'sh -i'
            - 'wget http'
            - 'curl http'
    condition: selection
level: high
falsepositives:
    - Legitimate network diagnostics that use shell metacharacters
    - Administrative commands with pipes (e.g., show | include)

YARA Rule

rule AOSCX_CLI_Command_Injection_CVE_2026_73768 {
    meta:
        author = "ValtersIT SOC"
        description = "Detects CLI logs containing command injection patterns for CVE-2026-73768"
        cve = "CVE-2026-73768"
        date = "2026-01-01"
        score = 70
    strings:
        $s1 = "; sh" ascii nocase
        $s2 = "|sh" ascii nocase
        $s3 = "$(" ascii
        $s4 = "`" ascii
        $s5 = "&;&" ascii
        $s6 = "cmd.exe" ascii
        $s7 = "/bin/sh" ascii
        $s8 = "whoami" ascii
        $s9 = "id;" ascii
        $s10 = "cat /etc/passwd" ascii
    condition:
        any of them and filesize < 1MB
}

Suricata IDS Rule

alert tcp any any -> $HOME_NET 22 (msg:"CVE-2026-73768 AOS-CX CLI command injection attempt"; flow:established,to_server; content:";sh"; http_uri; content:"$(​"; http_uri; reference:cve,2026-73768; sid:1000001; rev:1;)

*Note: Network-based detection of CLI injection is limited because the payload is transmitted inside an encrypted SSH session. This rule will only be effective if applied on an unencrypted management channel (e.g., telnet/serial console proxies) or on the network segment where an SSH-inspecting appliance can see decrypted traffic.

Elastic Detection

sequence by host.name with maxspan=5m
  [process where event.action=="process_started" and 
   process.args.* contains ";" or "&&" or "|" or "$(​"]
  [process where event.action=="process_started" and process.parent_process.name=="aoscx_cli_daemon"
   and process.name in ("sh", "bash", "zsh", "dash") and process.command_line contains ("whoami", "reboot", "rm /", "wget", "curl")]

Splunk SPL Query

index=network sourcetype=aoscx:cli 
    (command="*;sh*" OR command="*|sh*" OR command="*$(​)*" OR command="*`*" OR command="*&&*") 
    OR (process=* 
        AND parent_process="aoscx_cli_daemon" 
        AND (process="sh" OR process="bash" OR process="zsh") 
        AND (command="*whoami*" OR command="*reboot*" OR command="*wget*" OR command="*curl*" OR command="*/tmp/*"))
    | stats count min(_time) as first_seen max(_time) as last_seen by host, user, command
    | where count > 1

Wazuh OSSEC Rule

<group name="aoscx,">
  <rule id="100001" level="12">
    <if_sid>5715</if_sid>
    <match>aoscx_cli</match>
    <regex>command.*(\;|&&|\|\||\$\()</regex>
    <description>Possible AOS-CX CLI command injection attempt (CVE-2026-73768)</description>
    <group>attack_command_injection,</group>
  </rule>
  <rule id="100002" level="14">
    <if_sid>5715</if_sid>
    <match>aoscx_cli</match>
    <regex>exec.*sh|exec.*bash|exec.*python</regex>
    <description>Suspicious shell process spawned from AOS-CX CLI - possible CVE-2026-73768 exploitation</description>
    <group>attack_command_execution,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch Confidence: 2/4 — CLAIMED. A single source (NVD) indicates a patch is available. No independent vendor advisory or version-specific fix has been publicly confirmed. Do not assume you are protected until HPE formally releases an advisory and a version check has been performed.

1. Immediate Mitigations

• Restrict CLI access: Limit interactive CLI SSH sessions to only trusted management hosts via ACLs. Utilize management VLANs with strict firewall rules.
• Enforce RBAC (Role-Based Access Control): Reduce number of users with "config" or "admin" role privileges; monitor user accounts for least privilege.
• Disable unused CLI access paths: If serial console or telnet is enabled, disable them. If using SSH, enforce key-based authentication and disable password-based login.
• Set up AAA (Authentication, Authorization, Accounting): Route authentication through TACACS+/RADIUS to centralize and monitor login and command activity.
• Monitor for anomalous CLI activity: Enable audit logging and consider forwarding logs to a central SIEM.

2. Patch / Upgrade Steps

• Verify vendor advisory: Monitor HPE Security Bulletin site (https://support.hpe.com/hpesc/public/home) for an advisory referencing CVE-2026-73768.
• Apply the patch: When available, download the patched AOS-CX version and verify its checksum via HPE support. Install during a scheduled maintenance window.
• Test before production: Validate the patch in a lab environment matching your production configuration first.
• If the affected versions list in NVD is empty, assume all AOS-CX versions up to the date of the CVE are potentially affected.

3. Long-Term Hardening

• Maintain inventory: Track all AOS-CX devices and their exact firmware versions; establish an automated alert for new CVE announcements affecting HPE ArubaOS-CX.
• Enable automatic alerting: Subscribe to HPE Product Security Alerts (PSR).
• Network segmentation: Isolate management planes (OOB management networks) from user networks and segregate switch fabrics into security zones.
• Back up configurations routinely with checksums stored off-device; verify integrity on a regular basis.
• Establish a vulnerability management process: Patch infrastructure devices within 30 days of vendor advisory for critical/High CVEs.
• Review local accounts: Delete unused local accounts; change default passwords for recovery accounts immediately.

References

1. NVD Entry: cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-73768 (confirms CWE-20 classification and CVSS).
2. HPE Security Bulletin Portal: https://support.hpe.com/hpesc/public/home (search CVE-2026-73768 for the vendor advisory when published).
3. EPSS Data: FIRST.org EPSS feed — score 0.00122 for CVE-2026-73768, probability of exploitation in the wild.
4. CISA KEV: Not listed (kev.in cisa.gov) — no confirmed exploitation in the wild as of this report.

Threat actor campaigns / Exploit-in-the-wild evidence: None documented. No public exploit code has been demonstrated on proof-of-concept level; however, public availability of PoC information lowers the practical exploitation time-to-exploit metric. SOC teams should treat this as "likely to be exploited in the near-term" if the device is internet-facing with a low-privilege CLI user base.

Report generated by ValtersIT Cyber Threat Intelligence — based on NVD CVE data. All technical confidence statements adhere to the guiding data provided; any undisclosed operational details are representative of vulnerability-classes rather than specific implementations.