CVE-2022-43294 is a critical stack overflow vulnerability identified in the Tasmota firmware prior to commit 066878da4d4762a9b6cb169fdf353e804d735cfd. The flaw exists in the handling of the ClientPortPtr parameter within the RTSP session implementation, specifically in the file lib/libesp32/rtsp/CRtspSession.cpp. A stack overflow occurs when improper bounds checking or validation of this parameter allows an attacker to overwrite the stack memory, potentially leading to arbitrary code execution, denial of service, or system compromise. The vulnerability is remotely exploitable without authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The vulnerability affects Tasmota firmware versions before the specified commit, although exact version numbers are not provided. Tasmota is an open-source firmware widely used to control ESP8266 and ESP32-based IoT devices, including smart home appliances and sensors. Exploitation of this vulnerability could allow attackers to take control of affected IoT devices, disrupt their operation, or use them as pivot points for further network intrusion. The CVSS score of 9.8 reflects the critical nature of this vulnerability, with high impact on confidentiality, integrity, and availability. No known exploits in the wild have been reported yet, but the ease of exploitation and severity warrant immediate attention. The vulnerability is classified under CWE-787 (Out-of-bounds Write), a common and dangerous class of memory corruption bugs. The lack of a vendor or product name in the report suggests this is a community-driven or open-source project vulnerability rather than a commercial product issue. The patch addressing this vulnerability was introduced in the commit mentioned, and users of Tasmota firmware should update to the fixed version promptly to mitigate risk.

For European organizations, the impact of CVE-2022-43294 can be significant, especially those relying on IoT devices running Tasmota firmware for smart building management, industrial automation, or home automation. Compromise of these devices could lead to unauthorized access to internal networks, disruption of critical services, or data leakage. Given the critical severity and remote exploitability without authentication, attackers could leverage this vulnerability to gain persistent footholds in corporate or residential networks. This could facilitate lateral movement, espionage, or sabotage. Additionally, compromised IoT devices might be recruited into botnets, contributing to large-scale DDoS attacks affecting European infrastructure. The impact extends beyond individual devices to the broader network and organizational security posture. Since many European companies and consumers adopt IoT solutions for energy efficiency and operational monitoring, the vulnerability poses a tangible risk to operational continuity and data confidentiality. The absence of known exploits in the wild currently limits immediate widespread damage, but proactive mitigation is essential to prevent future exploitation.

1. Immediate firmware update: Organizations and users should upgrade all Tasmota devices to the version including the fix from commit 066878da4d4762a9b6cb169fdf353e804d735cfd or later. 2. Network segmentation: Isolate IoT devices running Tasmota firmware on separate VLANs or network segments to limit exposure and lateral movement in case of compromise. 3. Implement strict firewall rules: Block unnecessary inbound and outbound traffic to IoT devices, especially RTSP-related ports, to reduce attack surface. 4. Continuous monitoring: Deploy network intrusion detection systems (NIDS) and endpoint detection to identify anomalous behavior indicative of exploitation attempts. 5. Disable unused services: If RTSP functionality is not required, disable it on Tasmota devices to eliminate the attack vector. 6. Inventory and asset management: Maintain an up-to-date inventory of IoT devices and firmware versions to ensure timely patching and risk assessment. 7. Vendor and community engagement: Follow Tasmota community channels for updates and advisories to stay informed about new patches or exploit reports. 8. Incident response planning: Prepare response procedures specific to IoT device compromise to minimize damage and recovery time.