A vulnerability in the IGMP processing subsystem of Cisco Wireless LAN Controllers (WLC) could allow an unauthenticated, remote attacker to cause a DoS condition.
The vulnerability is due to improper validation of a specific field in certain IGMP message types. When messages are processed, the IGMP subsystem may perform a memory over-read. When subsequent processing is performed on the extraneous data an error may occur that results in a reload of the device. An attacker could exploit this vulnerability by injecting a malicious IGMP version 3 message onto the network that will be received and processed by an affected WLC. An exploit could allow the attacker to trigger a critical error on the WLC, resulting in a DoS condition while the device restarts.
The IGMPv3 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.
Indicators of Compromise
Cisco Wireless LAN Controller software versions prior to 126.96.36.199 and 188.8.131.52 are affected.
The vulnerability is due to improper validation of a specific field in certain IGMP message types by the IGMP processing subsystem of Cisco WLC.
An unauthenticated, remote attacker could exploit this vulnerability by injecting a malicious IGMP version 3 message onto the network that will be received and processed by a targeted device. Once processed, the IGMP subsystem on the targeted device may consume excessive amounts of memory, which could trigger a critical error and cause the device to reload, resulting in a DoS condition.
To exploit this vulnerability, an attacker may need access to trusted, internal networks to send malicious IGMP version 3 messages 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.
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.
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 email@example.com.
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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.