Rockwell Automation MicroLogix 1400 Controllers and 1756 ControlLogix Communications Modules An unauthenticated, remote threat actor could send a CIP connection request to an affected device, and upon successful connection, send a new IP configuration to the affected device even if the controller in the system is set to Hard RUN mode. When the affected device accepts this new IP configuration, a loss of communication occurs between the device and the rest of the system as the system traffic is still attempting to communicate with the device via the overwritten IP address.

An exploitable file write vulnerability exists in the memory module functionality of Allen Bradley Micrologix 1400 Series B FRN 21.2 and before. A specially crafted packet can cause a file write resulting in a new program being written to the memory module. An attacker can send an unauthenticated packet to trigger this vulnerability.

An exploitable access control vulnerability exists in the data, program, and function file permissions functionality of Allen Bradley Micrologix 1400 Series B FRN 21.2 and before. A specially crafted packet can cause a read or write operation resulting in disclosure of sensitive information, modification of settings, or modification of ladder logic. An attacker can send unauthenticated packets to trigger this vulnerability. Required Keyswitch State: REMOTE or PROG Description: This ability is leveraged in a larger exploit to flash custom firmware.

An exploitable insufficient resource pool vulnerability exists in the session communication functionality of Allen Bradley Micrologix 1400 Series B Firmware 21.2 and before. A specially crafted stream of packets can cause a flood of the session resource pool resulting in legitimate connections to the PLC being disconnected. An attacker can send unauthenticated packets to trigger this vulnerability.

An exploitable access control vulnerability exists in the data, program, and function file permissions functionality of Allen Bradley Micrologix 1400 Series B FRN 21.2 and before. A specially crafted packet can cause a read or write operation resulting in disclosure of sensitive information, modification of settings, or modification of ladder logic. An attacker can send unauthenticated packets to trigger this vulnerability. Required Keyswitch State: REMOTE or PROG or RUN Description: The value 0xffffffff is considered NaN for the Float data type. When a float is set to this value and used in the PLC, a fault is triggered. NOTE: This is not possible through RSLogix.

An exploitable access control vulnerability exists in the data, program, and function file permissions functionality of Allen Bradley Micrologix 1400 Series B FRN 21.2 and before. A specially crafted packet can cause a read or write operation resulting in disclosure of sensitive information, modification of settings, or modification of ladder logic. An attacker can send unauthenticated packets to trigger this vulnerability. Required Keyswitch State: REMOTE or PROG Associated Fault Codes: 0023, 002e, and 0037 Fault Type: Recoverable Description: The STI, EII, and HSC function files contain bits signifying whether or not a fault has occurred. Additionally there is a bit signaling the module to auto start. When these bits are set for any of the three modules and the device is moved into a run state, a fault is triggered.

An exploitable denial of service vulnerability exists in the Ethernet functionality of the Allen Bradley Micrologix 1400 Series B FRN 21.2 and below. A specially crafted packet can cause a device power cycle resulting in a fault state and deletion of ladder logic. An attacker can send one unauthenticated packet to trigger this vulnerability

An exploitable access control vulnerability exists in the data, program, and function file permissions functionality of Allen Bradley Micrologix 1400 Series B FRN 21.2 and before. A specially crafted packet can cause a read or write operation resulting in disclosure of sensitive information, modification of settings, or modification of ladder logic. An attacker can send unauthenticated packets to trigger this vulnerability. Required Keyswitch State: REMOTE or PROG Associated Fault Code: 0028 Fault Type: Non-User Description: Values 0x01 and 0x02 are invalid values for the user fault routine. By writing directly to the file it is possible to set these values. When this is done and the device is moved into a run state, a fault is triggered. NOTE: This is not possible through RSLogix.

An exploitable access control vulnerability exists in the data, program, and function file permissions functionality of Allen Bradley Micrologix 1400 Series B FRN 21.2 and before. A specially crafted packet can cause a read or write operation resulting in disclosure of sensitive information, modification of settings, or modification of ladder logic. An attacker can send unauthenticated packets to trigger this vulnerability. Required Keyswitch State: REMOTE Description: Any input or output can be forced, causing unpredictable activity from the PLC.

An exploitable denial of service vulnerability exists in the program download functionality of Allen Bradley Micrologix 1400 Series B FRN 21.2 and before. A specially crafted packet can cause a device fault resulting in halted operations. An attacker can send an unauthenticated packet to trigger this vulnerability.