CVE-2017-3881 Explained : Impact and Mitigation
Learn about CVE-2017-3881, a critical vulnerability in Cisco IOS and IOS XE Software that allows remote attackers to execute code with elevated privileges. Find mitigation steps and preventive measures here.
A vulnerability has been found in the processing code of the Cisco Cluster Management Protocol (CMP) used in Cisco IOS and Cisco IOS XE Software. This vulnerability could potentially allow a remote attacker without authentication to cause an affected device to reload or execute code with higher privileges. The Cluster Management Protocol utilizes Telnet internally as a signaling and command protocol between cluster members.
Understanding CVE-2017-3881
This CVE identifies a critical vulnerability in Cisco IOS and IOS XE Software that could lead to remote code execution.
What is CVE-2017-3881?
The vulnerability in the Cisco Cluster Management Protocol (CMP) processing code in Cisco IOS and Cisco IOS XE Software allows an unauthenticated remote attacker to reload an affected device or execute code with elevated privileges.
The Impact of CVE-2017-3881
- Attackers can exploit this vulnerability to execute arbitrary code, gain full control of the device, or cause a reload of the affected device.
Technical Details of CVE-2017-3881
This section provides detailed technical information about the vulnerability.
Vulnerability Description
The vulnerability is due to the failure to restrict the use of CMP-specific Telnet options to internal communications between cluster members and the incorrect processing of malformed CMP-specific Telnet options.
Affected Systems and Versions
This vulnerability affects various Cisco products, including Catalyst switches, Embedded Service 2020 switches, Enhanced Layer 2 EtherSwitch Service Module, and more.
Exploitation Mechanism
To exploit this vulnerability, an attacker needs to send malformed CMP-specific Telnet options while establishing a Telnet session with a targeted Cisco device configured to accept Telnet connections.
Mitigation and Prevention
Protect your systems from CVE-2017-3881 with the following steps:
Immediate Steps to Take
- Disable Telnet protocol where possible and use secure alternatives like SSH.
- Apply the latest security patches provided by Cisco.
Long-Term Security Practices
- Implement network segmentation to limit the impact of potential attacks.
- Regularly monitor and update your network security measures.
Patching and Updates
- Stay informed about security advisories from Cisco and apply patches promptly to mitigate risks.