CVE-2025-15233 is a heap-based buffer overflow vulnerability identified in the Tenda M3 router firmware version 1.0.0.13(4903). The vulnerability resides in the formSetAdInfoDetails function, specifically in the /goform/setAdInfoDetail endpoint, which processes several parameters including adName, smsPassword, smsAccount, weixinAccount, weixinName, smsSignature, adRedirectUrl, adCopyRight, smsContent, and adItemUID. Improper handling and insufficient bounds checking of these input parameters allow an attacker to overflow the heap memory. This overflow can corrupt adjacent memory structures, potentially leading to arbitrary code execution or denial of service conditions. The vulnerability is remotely exploitable without requiring authentication or user interaction, increasing its risk profile. The CVSS v4.0 score is 8.7 (high), reflecting the ease of remote exploitation and the significant impact on confidentiality, integrity, and availability. Although no confirmed exploits are currently observed in the wild, a public proof-of-concept exploit has been released, increasing the likelihood of active exploitation. The lack of available patches at the time of disclosure further elevates the threat level. This vulnerability affects a widely deployed consumer and small office router, which may be used in various organizational environments, including European enterprises and critical infrastructure.

The impact of CVE-2025-15233 on European organizations can be substantial. Successful exploitation can lead to remote code execution, allowing attackers to take full control of affected routers. This compromises network perimeter security, enabling interception or manipulation of network traffic, lateral movement within corporate networks, and potential deployment of further malware. Confidential data passing through the router could be exposed or altered, affecting data confidentiality and integrity. Additionally, exploitation could cause denial of service, disrupting business operations reliant on network connectivity. Given the remote, unauthenticated nature of the exploit, attackers can target vulnerable devices at scale. European organizations using Tenda M3 routers, especially in sectors like finance, healthcare, government, and critical infrastructure, face increased risk. The absence of patches at disclosure time means organizations must rely on network-level mitigations, increasing operational complexity and risk exposure.

1. Immediate mitigation should focus on restricting access to the router's management interface by implementing network segmentation and firewall rules to block external access to the /goform/setAdInfoDetail endpoint. 2. Disable remote management features if not strictly necessary to reduce the attack surface. 3. Monitor network traffic for unusual or suspicious requests targeting the vulnerable endpoint. 4. Deploy intrusion detection/prevention systems (IDS/IPS) with signatures tuned to detect exploitation attempts of this vulnerability. 5. Engage with Tenda for firmware updates and apply patches as soon as they become available. 6. For organizations unable to patch immediately, consider replacing vulnerable devices with alternative hardware not affected by this vulnerability. 7. Conduct thorough audits of network devices to identify all instances of Tenda M3 routers and assess exposure. 8. Educate IT staff about this vulnerability and ensure incident response plans include steps for potential exploitation scenarios.