CVE-2017-6773 : Security Advisory and Response

A security weakness has been identified in the Command Line Interface (CLI) of Cisco ASR 5000 Series Aggregated Services Routers operating on the Cisco StarOS system, allowing a local authenticated attacker to bypass CLI restrictions and execute commands on the underlying OS.

Understanding CVE-2017-6773

This CVE involves a vulnerability in the CLI of Cisco ASR 5000 Series Routers running the StarOS operating system, potentially enabling unauthorized command execution.

What is CVE-2017-6773?

The vulnerability in the CLI of Cisco ASR 5000 Series Routers on StarOS allows a local attacker with authentication to bypass CLI restrictions and run commands on the OS due to inadequate input validation.

The Impact of CVE-2017-6773

An authenticated local attacker can execute commands on the underlying OS, compromising system integrity.

Technical Details of CVE-2017-6773

This section provides detailed technical insights into the vulnerability.

Vulnerability Description

The vulnerability arises from insufficient input sanitization at the CLI, enabling attackers to craft scripts to bypass restrictions and launch the CLI from a command shell.

Affected Systems and Versions

Product: StarOS for ASR 5000 Series Aggregated Services Routers
Vendor: Cisco Systems, Inc.
Affected Version: 21.0.v0.65839

Exploitation Mechanism

Attackers can create scripts on the device to bypass CLI restrictions and execute unauthorized commands on the OS.

Mitigation and Prevention

Protect your systems from CVE-2017-6773 with these mitigation strategies.

Immediate Steps to Take

Apply vendor-supplied patches promptly.
Monitor network traffic for any signs of exploitation.
Restrict access to vulnerable systems.

Long-Term Security Practices

Regularly update and patch all software and firmware.
Implement strong authentication mechanisms.
Conduct security training for staff to recognize and report suspicious activities.

Patching and Updates

Cisco has released patches to address this vulnerability. Ensure all affected systems are updated with the latest patches to mitigate the risk of exploitation.