Talos Vulnerability Report


Ocularis Recorder VMS_VA Denial of Service Vulnerability

June 5, 2018
CVE Number



An exploitable denial of service vulnerability exists in the Ocularis Recorder functionality of Ocularis A specially crafted TCP packet can cause a process to terminate resulting in denial of service. An attacker can send a crafted TCP packet to trigger this vulnerability.

Tested Versions

Ocularis Recorder

Product URLs


CVSSv3 Score

7.5 - CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H


CWE-250 - Execution with Unnecessary Privileges


This binary listens for incoming TCP connections. When a client connects to this binary and sends any non expected data, the binary will respond with “Hello World!”. If the server receives the dispose command it will terminate the VMS_VA process.

this.tcpListener = new TcpListener(IPAddress.Any, 60801 + ConfigID);
Thread thread = new Thread(new ThreadStart(this.ListenForClients))
    Name = "VA CommServer V4 Listener"
if (str.StartsWith("dispose"))
    this.Running = false;
    bytes = Encoding.Default.GetBytes("Ack!");

The binary has a check to see if the receiving data starts with “dispose”. If it does the “this.Running” variable will be set to false which results in the process killing itself. There is no authentication required for this command to go through.

Crash Information


Exploit Proof-of-Concept

$ echo "dispose" | nc -nv 60801 60801 open


This vulnerability can be mitigated by not allowing VMS_VA.exe from accepting inbound connections. It is unclear if this will have any adverse affect on the Ocularis Recorder module as the product documentation explicitly states to allow inbound traffic to this binary.


2018-03-05 - Vendor Disclosure
2018-06-04 - Public Release


Discovered by Carlos Pacho of Cisco Talos.