CVE-2017-12238 : Security Advisory and Response
Learn about CVE-2017-12238, a vulnerability in Cisco IOS 15.0 through 15.4 for Cisco Catalyst 6800 Series Switches allowing unauthorized attackers to crash line cards, leading to denial of service.
A vulnerability in the Virtual Private LAN Service (VPLS) code of Cisco IOS 15.0 through 15.4 for Cisco Catalyst 6800 Series Switches could allow an unauthenticated, adjacent attacker to cause a C6800-16P10G or C6800-16P10G-XL type line card to crash, resulting in a denial of service (DoS) condition. This CVE was published on September 28, 2017, affecting Cisco IOS.
Understanding CVE-2017-12238
This CVE identifies a specific vulnerability in Cisco IOS software that impacts Cisco Catalyst 6800 Series Switches.
What is CVE-2017-12238?
The vulnerability allows an unauthorized attacker in close proximity to the affected device to crash a specific line card, leading to a denial of service situation. The flaw is related to memory management in the VPLS code of the software.
The Impact of CVE-2017-12238
- Unauthorized attackers can exploit the vulnerability to crash specific line cards, causing a denial of service scenario.
- Successful exploitation results in the crashing of a C6800-16P10G or C6800-16P10G-XL line card.
Technical Details of CVE-2017-12238
This section provides detailed technical information about the vulnerability.
Vulnerability Description
The vulnerability is caused by a memory management issue in the VPLS code of Cisco IOS software.
Affected Systems and Versions
- Cisco IOS 15.0 through 15.4
- Specifically affects Cisco Catalyst 6800 Series Switches
Exploitation Mechanism
- Attacker needs to create numerous VPLS-generated MAC entries in the MAC address table of the affected device.
- Requires the device to be configured with VPLS and have specific line cards designated.
Mitigation and Prevention
Steps to address and prevent the exploitation of CVE-2017-12238.
Immediate Steps to Take
- Apply the latest security patches provided by Cisco.
- Implement network segmentation to limit the impact of potential attacks.
- Monitor network traffic for any suspicious activity.
Long-Term Security Practices
- Regularly update and patch all network devices and software.
- Conduct security audits and assessments to identify vulnerabilities.
- Educate network administrators and users on best security practices.
Patching and Updates
- Cisco has released patches to address this vulnerability.
- Ensure all affected systems are updated with the latest software versions.