CVE-2017-12336 Explained : Impact and Mitigation
Learn about CVE-2017-12336, a vulnerability in Cisco NX-OS System Software allowing unauthorized access to the operating system. Find mitigation steps and affected products.
A vulnerability in the TCL scripting subsystem of Cisco NX-OS System Software could allow an authenticated, local attacker to escape the interactive TCL shell and gain unauthorized access to the underlying operating system of the device.
Understanding CVE-2017-12336
This CVE involves a flaw in the TCL scripting subsystem of Cisco NX-OS System Software that could be exploited by an authorized individual with local access to the device.
What is CVE-2017-12336?
The vulnerability arises from inadequate validation of user-supplied files assigned to the interactive TCL shell, enabling an attacker to bypass the scripting sandbox and execute arbitrary commands on the underlying operating system.
The Impact of CVE-2017-12336
- An attacker with local access and administrative privileges can gain illicit access to the device's operating system.
- Affected products include various Cisco Nexus switches and Unified Computing System Manager.
Technical Details of CVE-2017-12336
This section provides more technical insights into the vulnerability.
Vulnerability Description
The flaw allows an attacker to execute unauthorized commands on the device's operating system by evading the scripting sandbox.
Affected Systems and Versions
- Cisco NX-OS System Software running on Multilayer Director Switches, Nexus switches, and Unified Computing System Manager.
Exploitation Mechanism
- Attacker needs local access and administrative or tclsh execution privileges to exploit the vulnerability.
Mitigation and Prevention
Protecting systems from CVE-2017-12336 requires immediate actions and long-term security practices.
Immediate Steps to Take
- Apply relevant patches and updates from Cisco.
- Restrict access to authorized personnel only.
- Monitor and audit TCL script activities.
Long-Term Security Practices
- Regular security training for staff on best practices.
- Implement least privilege access controls.
- Conduct regular security assessments and audits.
Patching and Updates
- Stay informed about security advisories from Cisco.
- Apply patches promptly to mitigate the vulnerability.