A vulnerability was found in Linux Kernel's Wi-Fi implementation. An attacker within wireless range can inject a control packet fragment where the kernel does not verify the Message Integrity Check (authenticity) of fragmented TKIP frames.

Upstream patch: https://lore.kernel.org/linux-wireless/20210511180259.159598-1-johannes@sipsolutions.net/ https://lore.kernel.org/linux-wireless/20210511200110.c3f1d42c6746.I795593fcaae941c471425b8c7d5f7bb185d29142@changeid/

A vulnerability was found in Linux Kernel. Where the Wifi implementations accept plaintext frames in a protected Wi-Fi network. An adversary can abuse this to inject arbitrary data frames independent of the network configuration.

Upstream patch: https://lore.kernel.org/linux-wireless/20210511180259.159598-1-johannes@sipsolutions.net/

A flaw was found in the Linux kernels wifi implementation. An attacker connected to the wireless network can send 'authentication and key management' frames to any participant on the network. These frames are only intended to be sent from the controlling access point however the kernel did not prevent retransmission of these packets from non-controlling nodes.

Upstream fix: https://lore.kernel.org/linux-wireless/20210511200110.cb327ed0cabe.Ib7dcffa2a31f0913d660de65ba3c8aca75b1d10f@changeid/

A flaw was found in the Linux kernels wifi implementation. An attacker within wireless broadcast range can inject custom data into the wireless communication circumventing checks on the data. This can cause the frame to pass checks and be considered a valid frame of a different type.

A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to hijack an AnyConnect VPN session or cause a denial of service (DoS) condition for individual users of the AnyConnect VPN service on an affected device. This vulnerability is due to weak entropy for handlers that are used during the VPN authentication process as well as a race condition that exists in the same process. An attacker could exploit this vulnerability by correctly guessing an authentication handler and then sending crafted HTTPS requests to an affected device. A successful exploit could allow the attacker to take over the AnyConnect VPN session from a target user or prevent the target user from establishing an AnyConnect VPN session with the affected device.

A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a DoS condition for targeted users of the AnyConnect service on an affected device.

This vulnerability is due to insufficient entropy for handlers that are used during SSL VPN session establishment. An unauthenticated attacker could exploit this vulnerability by brute forcing valid session handlers. An authenticated attacker could exploit this vulnerability by connecting to the AnyConnect VPN service of an affected device to retrieve a valid session handler and, based on that handler, predict further valid session handlers. The attacker would then send a crafted HTTPS request using the brute-forced or predicted session handler to the AnyConnect VPN server of the device. A successful exploit could allow the attacker to terminate targeted SSL VPN sessions, forcing remote users to initiate new VPN connections and reauthenticate.

Multiple vulnerabilities in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a DoS condition in the AnyConnect service on an affected device.

These vulnerabilities are due to insufficient validation of client-supplied parameters while establishing an SSL VPN session. An attacker could exploit these vulnerabilities by sending a crafted HTTPS request to the VPN server of an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to restart, resulting in the failure of the established SSL VPN connections and forcing remote users to initiate a new VPN connection and reauthenticate. A sustained attack could prevent new SSL VPN connections from being established.

Note: When the attack traffic stops, the Cisco AnyConnect VPN server recovers gracefully without requiring manual intervention.

Multiple vulnerabilities in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a DoS condition in the AnyConnect service on an affected device.

These vulnerabilities are due to insufficient validation of client-supplied parameters while establishing an SSL VPN session. An attacker could exploit these vulnerabilities by sending a crafted HTTPS request to the VPN server of an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to restart, resulting in the failure of the established SSL VPN connections and forcing remote users to initiate a new VPN connection and reauthenticate. A sustained attack could prevent new SSL VPN connections from being established.

Note: When the attack traffic stops, the Cisco AnyConnect VPN server recovers gracefully without requiring manual intervention.

A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a DoS condition in the AnyConnect service on an affected device.

This vulnerability is due to insufficient resource management when establishing TLS/SSL sessions. An attacker could exploit this vulnerability by sending a series of crafted TLS/SSL messages to the VPN server of an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to stop accepting new connections, preventing new SSL VPN connections from being established. Existing SSL VPN sessions are not impacted.

Note: When the attack traffic stops, the Cisco AnyConnect VPN server recovers gracefully without requiring manual intervention.

Multiple vulnerabilities in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a DoS condition in the AnyConnect service on an affected device.

These vulnerabilities are due to insufficient validation of client-supplied parameters while establishing an SSL VPN session. An attacker could exploit these vulnerabilities by sending a crafted HTTPS request to the VPN server of an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to restart, resulting in the failure of the established SSL VPN connections and forcing remote users to initiate a new VPN connection and reauthenticate. A sustained attack could prevent new SSL VPN connections from being established.

Note: When the attack traffic stops, the Cisco AnyConnect VPN server recovers gracefully without requiring manual intervention.

A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z Series Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device.

This vulnerability is due to insufficient resource management while establishing SSL VPN sessions. An attacker could exploit this vulnerability by sending a series of crafted HTTPS requests to the VPN server of an affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to stop accepting new connections, preventing new SSL VPN connections from being established. Existing SSL VPN sessions are not impacted.

Note: When the attack traffic stops, the Cisco AnyConnect VPN server recovers gracefully without requiring manual intervention.

A vulnerability in the local status page functionality of the Cisco Meraki MR, MS, MX, Z1, and Z3 product lines could allow an authenticated, remote attacker to modify device configuration files. The vulnerability occurs when handling requests to the local status page. An exploit could allow the attacker to establish an interactive session to the device with elevated privileges. The attacker could then use the elevated privileges to further compromise the device or obtain additional configuration data from the device that is being exploited.

A flaw was found in the Linux kernel's wifi implementation wherein an attacker within wireless range is able to abuse a logic flaw in the wifi implementation by reassembling packets from multiple fragments under different keys and they would be treated as valid. This allows an attacker to send a fragment under an incorrect key and be treated as a valid fragment under the new key.

Upstream patch: https://lore.kernel.org/linux-wireless/20210511200110.3f8290e59823.I622a67769ed39257327a362cfc09c812320eb979@changeid/

A vulnerability in the Cisco AnyConnect VPN server of Cisco Meraki MX and Cisco Meraki Z3 Teleworker Gateway devices could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient validation of client-supplied parameters while establishing an SSL VPN session. An attacker could exploit this vulnerability by crafting a malicious request and sending it to the affected device. A successful exploit could allow the attacker to cause the Cisco AnyConnect VPN server to crash and restart, resulting in the failure of the established SSL VPN connections and forcing remote users to initiate a new VPN connection and re-authenticate. A sustained attack could prevent new SSL VPN connections from being established. Note: When the attack traffic stops, the Cisco AnyConnect VPN server recovers gracefully without requiring manual intervention. Cisco Meraki has released software updates that address this vulnerability.