CVE-2020-8466: Trend Micro InterScan Web Security Virtual Appliance command injection via password

Automated analysis

Generated by VULONE's analysis model from the NVD record, CISA KEV and EPSS data on 19 September 2026. Confidence: medium.

critical priorityUnauthenticated network-reachable command injection with CVSS 9.8, high EPSS and public exploit detail makes this an urgent patch target.

What it is

Trend Micro InterScan Web Security Virtual Appliance 6.5 SP2 with improved password hashing enabled contains an OS command injection flaw (CWE-78). An unauthenticated attacker can execute certain commands by supplying a manipulated password. With a CVSS 3.1 score of 9.8 and network reachability, this is a severe pre-auth issue for exposed appliances.

Impact

An unauthenticated attacker can run arbitrary commands on the appliance, leading to full compromise of confidentiality, integrity and availability. This can expose traffic inspection data and allow the device to be used as a pivot into the network.

Attack surface

Reachable over the network (AV:N) with no privileges (PR:N) and no user interaction (UI:N), per the CVSS vector. The description indicates the manipulated password is supplied to a password-handling path, so the entry point is the authentication or password-processing interface of the appliance.

Exploitation

Not listed in CISA KEV, but EPSS is high at 0.64 (99th percentile) and the references include an Exploit-tagged third-party advisory, indicating public exploit detail exists. No ransomware association is documented.

What to do

• Apply the vendor fix referenced in Trend Micro solution 000283077; patch or upgrade the appliance as directed.
• If patching is not immediately possible, restrict network access to the appliance management and authentication interfaces to trusted hosts only.
• Disable or avoid the improved password hashing mode if the vendor guidance permits, since the flaw is described as present when that method is enabled.
• Monitor the appliance for signs of compromise and rotate credentials and secrets stored on it after remediation.
• Isolate the appliance on a segmented management network so a compromise cannot be used to pivot.

Detection

• Review appliance and web server logs for authentication attempts with malformed or unusual password values.
• Alert on unexpected child processes or shell activity spawned by the appliance's web or authentication service.
• Monitor for outbound connections from the appliance to hosts it does not normally contact.
• Check for unauthorized changes to appliance configuration, files or scheduled tasks.

This assessment is produced automatically and is not human-reviewed. Verify against the vendor advisory before acting on it.