SSD Advisory – Trend Micro Interscan Web Security Virtual Appliance Multiple Vulnerabilities

Vulnerabilities Summary
The following advisory describes three (3) vulnerabilities found in Trend Micro Interscan Web Security Virtual Appliance version 6.5.

“The Trend Micro Hybrid Cloud Security solution, powered by XGen security, delivers a blend of cross-generational threat defense techniques that have been optimized to protect physical, virtual, and cloud workloads.”

The vulnerabilities found in Trend Micro Interscan Web Security Virtual Appliance:

1. XML External Entity (XXE) that lead to arbitrary file disclosure
2. Local Privilege Escalation
3. Remote code execution

Credit
An independent security researcher has reported this vulnerability to Beyond Security’s SecuriTeam Secure Disclosure program.

Vendor response
Trend Micro has released patches to address these vulnerabilities and issued the following advisory: https://success.trendmicro.com/solution/1117412

Vulnerabilities Details
XML External Entity (XXE) that lead to arbitrary file disclosure
Trend Micro Security Manager uses an outdated REST API (resteasy-jaxrs-2.3.5.Final.jar). The library suffers from an XXE vulnerability that can be exploited using Parameter Entities.

Proof of Concept
By sending the following POST request, an attacker can gain the victims “/etc/shadow”

Local Privilege Escalation
Admin users have access via the web interface to the SSH configuration settings. The port settings are not properly handled and allow injecting shell commands as the root user.

In the above code, the SSHPort= parameter does not sanitize the incoming data. An attacker can use this to inject commands that will run as root on the victim’s machine.

Proof of Concept
The following POST request will call the sleep command with a value of 60 seconds:

Remote code execution
Trend Micro Interscan Web Security Virtual Appliance has a default user with sudo privileges named iscan. This user is locked out but it can access certain elevated functions.

In the above POST request, we can see the page has several parameters that are vulnerable and that we can inject malicious parameters through them: netid, netmask, router, and interface_vlanid_sel

Proof of Concept