CVE-2017-12319 : Exploit Details and Defense Strategies
Discover the impact of CVE-2017-12319, a vulnerability in Cisco IOS XE Software affecting BGP over EVPN. Learn about affected systems, exploitation, and mitigation steps.
A security flaw has been discovered in Cisco IOS XE Software, specifically in the Border Gateway Protocol (BGP) over Ethernet Virtual Private Network (EVPN). This vulnerability could potentially allow an unauthorized attacker to cause a targeted device to reload, resulting in a denial of service (DoS) situation. The issue arises due to modifications made in the implementation of the BGP MPLS-Based Ethernet VPN RFC (RFC 7432) draft in different releases of the IOS XE software.
Understanding CVE-2017-12319
This CVE involves a vulnerability in the BGP over EVPN for Cisco IOS XE Software.
What is CVE-2017-12319?
The vulnerability allows an attacker to send a specially crafted BGP packet to a device, causing it to reload or corrupt the BGP routing table, leading to a DoS scenario.
The Impact of CVE-2017-12319
- Unauthorized attackers can cause targeted devices to reload, resulting in a DoS situation
- Potential corruption of the BGP routing table, leading to network instability
Technical Details of CVE-2017-12319
This section provides technical insights into the vulnerability.
Vulnerability Description
- Occurs in the BGP over EVPN for Cisco IOS XE Software
- Triggered by crafted BGP packets after BGP session establishment
Affected Systems and Versions
- Vulnerable versions: Cisco IOS XE Software versions earlier than 16.3 with BGP EVPN configurations
- Devices not configured for EVPN are not susceptible
Exploitation Mechanism
- Attacker sends a specially crafted BGP packet to the affected device
- IP address length field may be incorrectly calculated
Mitigation and Prevention
Steps to address and prevent exploitation of CVE-2017-12319.
Immediate Steps to Take
- Apply patches provided by Cisco to fix the vulnerability
- Disable BGP EVPN configurations if not required
Long-Term Security Practices
- Regularly update and patch Cisco IOS XE Software
- Implement network segmentation and access controls
Patching and Updates
- Cisco has assigned Bug IDs CSCui67191 and CSCvg52875 to address this vulnerability