A vulnerability in the IPv6 snooping feature from the first-hop security features in Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload.
The vulnerability is due to insufficient Control Plane Protection (CPPr) against specific IPv6 ND packets. An attacker could exploit this vulnerability by sending a flood of traffic consisting of specific IPv6 ND packets to an affected device where the IPv6 snooping feature is configured.
Cisco has confirmed the vulnerability in a security advisory and released software updates.
Indicators of Compromise
Customers are advised to use the Cisco IOS Software Checker tool to determine whether devices are running an affected release of Cisco IOS Software. The tool also provides information about releases that correct the vulnerabilities.
Cisco has published a list of affected Cisco IOS XE Software releases in the security advisory. The "Vendor Announcements" section of this alert contains a link to the advisory.
The vulnerability is due to insufficient CPPr against specific IPv6 neighbor discovery (ND) packets sent to a device running an affected release of Cisco IOS or IOS XE Software.
An unauthenticated, remote attacker could exploit this vulnerability by sending large numbers of specific IPv6 ND packets to a targeted device. A successful exploit could cause the device to reload, resulting in a DoS condition.
To exploit this vulnerability, the attacker would need to send specific IPv6 ND packets to the targeted device, making exploitation more difficult in environments that restrict network access from untrusted sources. In addition, the attacker may need to acquire additional information about the targeted device prior to an exploit attempt, such as whether the IPv6 snooping feature is configured on the device. This feature needs to be configured for a successful exploit.
Cisco indicates through the CVSS score that functional code exists; however, the code is not known to be publicly available.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Cisco customers with active contracts can obtain updates through the Software Center at the following link: Cisco. Cisco customers without contracts can obtain upgrades by contacting the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via email at firstname.lastname@example.org.
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Cisco Multivendor Vulnerability Alerts respond to vulnerabilities identified in third-party vendors' products. These alerts contain information compiled from diverse sources and provide comprehensive technical descriptions, objective analytical assessments, workarounds and practical safeguards, and links to vendor advisories and patches.