Tcp Ip Stack Mqtt
Monthly
An out-of-bounds write in the MQTT client module of the lwIP TCP/IP stack lets an adversary who controls or impersonates the MQTT broker that a device connects to corrupt heap/stack memory and potentially achieve full code execution on that device. Only devices built with lwIP's optional MQTT client compiled in are exposed, and because MQTT connections are client-initiated the device is not directly reachable inbound: the attacker must operate a malicious broker, compromise the legitimate broker, or hold a man-in-the-middle position on the client-to-broker path (feasible where TLS is absent or certificate validation is disabled). No authentication or user interaction is required once that broker-side position is achieved, but no public exploit code has been identified at time of analysis and no CISA KEV listing exists; the vendor CVSS 4.0 score of 9.3 (AV:N/AC:L/AT:N) presents this as trivially exploitable, whereas the assessed CVSS 3.1 vector (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H) reflects the significant broker-control/MITM prerequisite.
An out-of-bounds write in the MQTT client module of the lwIP TCP/IP stack lets an adversary who controls or impersonates the MQTT broker that a device connects to corrupt heap/stack memory and potentially achieve full code execution on that device. Only devices built with lwIP's optional MQTT client compiled in are exposed, and because MQTT connections are client-initiated the device is not directly reachable inbound: the attacker must operate a malicious broker, compromise the legitimate broker, or hold a man-in-the-middle position on the client-to-broker path (feasible where TLS is absent or certificate validation is disabled). No authentication or user interaction is required once that broker-side position is achieved, but no public exploit code has been identified at time of analysis and no CISA KEV listing exists; the vendor CVSS 4.0 score of 9.3 (AV:N/AC:L/AT:N) presents this as trivially exploitable, whereas the assessed CVSS 3.1 vector (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H) reflects the significant broker-control/MITM prerequisite.