CVE-2025-69766 is a stack-based buffer overflow vulnerability identified in the Tenda AX3 router firmware version 16.03.12.11. The flaw exists in the formGetIptv function, which improperly handles the citytag stack buffer, leading to potential memory corruption. This vulnerability allows remote attackers to execute arbitrary code on the affected device without requiring any authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). The vulnerability is categorized under CWE-121 (Stack-based Buffer Overflow), a common and dangerous class of memory corruption issues. Exploitation could result in full compromise of the router, enabling attackers to manipulate network traffic, intercept data, or pivot into internal networks. Despite no known exploits currently in the wild, the critical CVSS score of 9.8 reflects the high impact on confidentiality, integrity, and availability. The vulnerability affects a widely used consumer and small business router model, which is often deployed in home and enterprise environments. The absence of available patches increases the urgency for mitigation. Attackers could leverage this vulnerability to disrupt network operations or establish persistent footholds within targeted networks.

For European organizations, the impact of this vulnerability is substantial. Compromise of Tenda AX3 routers could lead to unauthorized access to internal networks, interception of sensitive communications, and disruption of network services. This is particularly critical for organizations relying on IPTV services or those using these routers as part of their network infrastructure. The vulnerability could facilitate lateral movement within corporate networks, data exfiltration, or deployment of further malware. Given the criticality and ease of exploitation, attackers could target sectors such as telecommunications, media, government agencies, and enterprises with remote work setups. The potential for widespread disruption and data breaches poses significant operational and reputational risks. Additionally, the lack of patches could prolong exposure, increasing the window of opportunity for attackers.

1. Immediately isolate Tenda AX3 routers from untrusted networks and restrict management interfaces to trusted IP addresses only. 2. Disable IPTV-related services or features if not required, reducing the attack surface associated with the vulnerable formGetIptv function. 3. Implement network segmentation to limit the impact of a compromised router and prevent lateral movement. 4. Monitor network traffic for unusual patterns or attempts to exploit the vulnerability, using IDS/IPS solutions with updated signatures. 5. Engage with Tenda support channels to obtain firmware updates or patches as soon as they become available. 6. If patching is delayed, consider replacing vulnerable devices with alternative hardware from vendors with timely security support. 7. Educate IT staff about the vulnerability and ensure incident response plans include scenarios involving router compromise. 8. Regularly audit network devices for firmware versions and known vulnerabilities to maintain situational awareness.