CVE-2025-15253 is a stack-based buffer overflow vulnerability identified in the Tenda M3 router firmware version 1.0.0.13(4903). The flaw exists in an unspecified function handling the cmdinput parameter within the /goform/exeCommand endpoint. This endpoint likely processes command inputs sent via HTTP requests to the router's management interface. Due to insufficient bounds checking on cmdinput, an attacker can craft a malicious request that overflows the stack buffer, potentially overwriting the return address or other control data. This enables remote code execution (RCE) without requiring authentication or user interaction, as the vulnerability is accessible over the network (AV:N) and has low attack complexity (AC:L). The CVSS 4.0 vector indicates no privileges are needed (PR:L means low privileges, but the description suggests no authentication is required), no user interaction is necessary, and the impact on confidentiality, integrity, and availability is high. The vulnerability is critical because it allows attackers to gain control over the router, potentially intercepting or manipulating network traffic, deploying malware, or pivoting into internal networks. While no exploits are currently known in the wild, public disclosure of exploit code increases the likelihood of active exploitation. The lack of available patches at the time of publication necessitates immediate defensive measures to mitigate risk.

For European organizations, exploitation of this vulnerability could lead to severe consequences including unauthorized network access, interception of sensitive communications, disruption of internet connectivity, and compromise of internal systems through lateral movement. Organizations relying on Tenda M3 routers for critical infrastructure or business operations face risks to data confidentiality, system integrity, and service availability. The ability to execute code remotely without authentication makes this vulnerability particularly dangerous in environments where routers are exposed to untrusted networks or lack proper segmentation. Attackers could leverage this flaw to establish persistent footholds, exfiltrate data, or launch further attacks within corporate or governmental networks. The impact is magnified in sectors such as finance, healthcare, telecommunications, and public administration, where network reliability and data protection are paramount.

Immediate mitigation steps include isolating affected Tenda M3 routers from untrusted networks and restricting access to the /goform/exeCommand endpoint via firewall rules or access control lists. Network administrators should disable remote management interfaces or restrict them to trusted IP addresses only. Monitoring network traffic for unusual requests targeting /goform/exeCommand can help detect exploitation attempts. Since no official patches are currently available, organizations should engage with Tenda support for firmware updates and apply them promptly once released. Employing network segmentation to separate critical assets from vulnerable devices reduces potential attack surface. Additionally, deploying intrusion detection/prevention systems (IDS/IPS) with signatures targeting this vulnerability can provide early warning and block exploit attempts. Regularly auditing router configurations and firmware versions across the network ensures timely identification of vulnerable devices.