CVE-2017-6738 : Security Advisory and Response

Cisco IOS and IOS XE versions 12.0 through 12.4 and 15.0 through 15.6, as well as IOS XE versions 2.2 through 3.17, contain vulnerabilities in the Simple Network Management Protocol (SNMP) subsystem that could allow remote code execution or system reload.

Understanding CVE-2017-6738

This CVE identifies vulnerabilities in the SNMP subsystem of Cisco IOS and IOS XE versions, potentially exploited by authenticated remote attackers.

What is CVE-2017-6738?

The vulnerabilities in the SNMP subsystem of affected Cisco software versions could enable attackers to execute code on the system or cause it to reload by sending manipulated SNMP packets.

The Impact of CVE-2017-6738

Remote attackers, authenticated on the system, could exploit the vulnerabilities to execute code or trigger system reloads.
Attackers need to send crafted SNMP packets to the system using IPv4 or IPv6.
Only traffic directed towards the affected system can be used to exploit these vulnerabilities.
The vulnerabilities stem from buffer overflow issues within the SNMP subsystem.
Versions 1, 2c, and 3 of SNMP are all affected.

Technical Details of CVE-2017-6738

The technical aspects of the vulnerability in Cisco IOS and IOS XE versions.

Vulnerability Description

The vulnerabilities allow remote code execution or system reload through manipulated SNMP packets.

Affected Systems and Versions

Cisco IOS versions 12.0 through 12.4 and 15.0 through 15.6, and IOS XE versions 2.2 through 3.17.

Exploitation Mechanism

Attackers need to send manipulated SNMP packets to the system using IPv4 or IPv6.
Knowledge of SNMP read-only community string or user credentials is required for exploitation.

Mitigation and Prevention

Steps to mitigate and prevent exploitation of CVE-2017-6738.

Immediate Steps to Take

Disable SNMP if not strictly required.
Implement access control lists (ACLs) to restrict SNMP traffic.
Apply the latest security patches and updates from Cisco.

Long-Term Security Practices

Regularly review and update SNMP configurations.
Monitor network traffic for any suspicious SNMP activities.

Patching and Updates

Apply the patches provided by Cisco to address the vulnerabilities in affected versions.