Cisco Wireless LAN Controller contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
A vulnerability in the multicast listener discovery (MLD) service of a Cisco WLC configured for IPv6 could allow an unauthenticated, remote attacker to cause a denial of service condition.
The vulnerability is due to a failure to properly parse malformed MLD version 2 messages. An attacker could exploit this vulnerability by submitting a malformed MLDv2 packet to a multicast-enabled network that the Cisco WLC is listening for. An exploit could allow the attacker to trigger a critical error on the WLC, resulting in a DoS condition while the device restarts.
The MLDv2 Snooping feature is disabled by default and must be explicitly configured by an administrator for a device to be vulnerable.
Cisco has confirmed the vulnerability in a security advisory and released software updates.
Cisco Wireless LAN Controller software versions prior to 220.127.116.11 and 18.104.22.168 are affected.
To exploit this vulnerability, an attacker may need access to trusted, internal networks to send malformed MLDv2 packets to an affected device. This access requirement may reduce the likelihood of a successful exploit.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
An unauthenticated, remote attacker could exploit this vulnerability to cause an affected device to reload, resulting in a DoS condition.
The vulnerability is due to improper parsing of malformed MLD version 2 messages by an affected device.
An unauthenticated, remote attacker could exploit this vulnerability by submitting a malformed MLDv2 packet to a multicast-enabled network that the targeted device is listening for. Once processed, the malformed MLDv2 packet could trigger a critical error and cause the device to reload, resulting in a DoS condition.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators are advised to monitor affected systems.
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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