CVE-2025-20709: CWE-120 Classic Buffer Overflow in MediaTek, Inc. MT6890, MT7915, MT7916, MT7981, MT7986
In wlan AP driver, there is a possible out of bounds write due to an incorrect bounds check. This could lead to remote (proximal/adjacent) escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00415809; Issue ID: MSV-3405.
AI Analysis
Technical Summary
CVE-2025-20709 is a buffer overflow vulnerability classified under CWE-120 found in the WLAN AP driver of several MediaTek chipsets, including MT6890, MT7915, MT7916, MT7981, and MT7986. The vulnerability stems from an incorrect bounds check in the driver code, which allows an out-of-bounds write to occur. This flaw can be exploited remotely by an attacker in proximity (adjacent wireless range) without requiring user interaction or additional execution privileges. The vulnerability enables escalation of privileges on the affected device, potentially allowing the attacker to execute arbitrary code or gain unauthorized control over the device’s wireless functions. Affected versions include SDK release 7.6.7.2 and earlier, as well as OpenWrt versions 19.07 and 21.02 for the MT6890 chipset. Although no public exploits have been reported yet, the nature of the vulnerability and the lack of required user interaction make it a significant risk. The issue was reserved in November 2024 and published in October 2025, with no CVSS score assigned at the time of reporting. The vulnerability affects embedded wireless access points and devices using these MediaTek chipsets, which are commonly found in consumer and enterprise networking equipment. The absence of a patch link suggests that fixes may be pending or distributed through vendor-specific updates. Due to the wireless proximity exploitation vector, attackers do not need network access credentials, increasing the attack surface. This vulnerability could be leveraged to compromise network infrastructure, intercept or manipulate wireless traffic, or disrupt service availability.
Potential Impact
For European organizations, this vulnerability poses a significant threat to wireless network infrastructure security. Exploitation could lead to unauthorized privilege escalation on access points or embedded devices, enabling attackers to manipulate network traffic, intercept sensitive communications, or disrupt network availability. This undermines confidentiality, integrity, and availability of critical network services. Organizations relying on MediaTek-based wireless equipment in offices, industrial environments, or public Wi-Fi deployments are at risk of targeted attacks from nearby adversaries. The lack of user interaction requirement and the ability to exploit remotely within wireless range increase the likelihood of successful attacks. Potential impacts include data breaches, lateral movement within corporate networks, and denial of service conditions. Given the widespread use of OpenWrt in embedded devices and the presence of these chipsets in consumer and enterprise-grade hardware, the vulnerability could affect a broad range of devices. This is particularly concerning for sectors with high wireless dependency such as telecommunications, manufacturing, and public administration. The absence of known exploits currently provides a window for proactive mitigation, but the risk remains high due to the vulnerability’s characteristics.
Mitigation Recommendations
1. Apply patches and firmware updates from MediaTek or device vendors as soon as they become available to address CVE-2025-20709. 2. For devices running OpenWrt, upgrade to versions beyond 21.02 or apply vendor-provided patches that fix the vulnerability. 3. Implement strict wireless network segmentation to isolate critical infrastructure from general wireless access, reducing exposure to adjacent attackers. 4. Employ wireless intrusion detection and prevention systems (WIDS/WIPS) to monitor for anomalous or suspicious wireless activity indicative of exploitation attempts. 5. Limit physical proximity access to wireless access points by securing device locations and restricting unauthorized personnel. 6. Regularly audit and inventory network devices to identify those using affected MediaTek chipsets and prioritize them for remediation. 7. Use network access control (NAC) to enforce authentication and authorization policies, mitigating risks from compromised devices. 8. Educate IT staff on the specifics of this vulnerability to ensure rapid response and incident handling if exploitation is suspected. 9. Consider temporary disabling or restricting vulnerable wireless interfaces where feasible until patches are applied. 10. Collaborate with vendors and security communities to stay informed about patch releases and emerging exploit reports.
Affected Countries
Germany, France, United Kingdom, Italy, Netherlands, Spain, Poland
CVE-2025-20709: CWE-120 Classic Buffer Overflow in MediaTek, Inc. MT6890, MT7915, MT7916, MT7981, MT7986
Description
In wlan AP driver, there is a possible out of bounds write due to an incorrect bounds check. This could lead to remote (proximal/adjacent) escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: WCNCR00415809; Issue ID: MSV-3405.
AI-Powered Analysis
Technical Analysis
CVE-2025-20709 is a buffer overflow vulnerability classified under CWE-120 found in the WLAN AP driver of several MediaTek chipsets, including MT6890, MT7915, MT7916, MT7981, and MT7986. The vulnerability stems from an incorrect bounds check in the driver code, which allows an out-of-bounds write to occur. This flaw can be exploited remotely by an attacker in proximity (adjacent wireless range) without requiring user interaction or additional execution privileges. The vulnerability enables escalation of privileges on the affected device, potentially allowing the attacker to execute arbitrary code or gain unauthorized control over the device’s wireless functions. Affected versions include SDK release 7.6.7.2 and earlier, as well as OpenWrt versions 19.07 and 21.02 for the MT6890 chipset. Although no public exploits have been reported yet, the nature of the vulnerability and the lack of required user interaction make it a significant risk. The issue was reserved in November 2024 and published in October 2025, with no CVSS score assigned at the time of reporting. The vulnerability affects embedded wireless access points and devices using these MediaTek chipsets, which are commonly found in consumer and enterprise networking equipment. The absence of a patch link suggests that fixes may be pending or distributed through vendor-specific updates. Due to the wireless proximity exploitation vector, attackers do not need network access credentials, increasing the attack surface. This vulnerability could be leveraged to compromise network infrastructure, intercept or manipulate wireless traffic, or disrupt service availability.
Potential Impact
For European organizations, this vulnerability poses a significant threat to wireless network infrastructure security. Exploitation could lead to unauthorized privilege escalation on access points or embedded devices, enabling attackers to manipulate network traffic, intercept sensitive communications, or disrupt network availability. This undermines confidentiality, integrity, and availability of critical network services. Organizations relying on MediaTek-based wireless equipment in offices, industrial environments, or public Wi-Fi deployments are at risk of targeted attacks from nearby adversaries. The lack of user interaction requirement and the ability to exploit remotely within wireless range increase the likelihood of successful attacks. Potential impacts include data breaches, lateral movement within corporate networks, and denial of service conditions. Given the widespread use of OpenWrt in embedded devices and the presence of these chipsets in consumer and enterprise-grade hardware, the vulnerability could affect a broad range of devices. This is particularly concerning for sectors with high wireless dependency such as telecommunications, manufacturing, and public administration. The absence of known exploits currently provides a window for proactive mitigation, but the risk remains high due to the vulnerability’s characteristics.
Mitigation Recommendations
1. Apply patches and firmware updates from MediaTek or device vendors as soon as they become available to address CVE-2025-20709. 2. For devices running OpenWrt, upgrade to versions beyond 21.02 or apply vendor-provided patches that fix the vulnerability. 3. Implement strict wireless network segmentation to isolate critical infrastructure from general wireless access, reducing exposure to adjacent attackers. 4. Employ wireless intrusion detection and prevention systems (WIDS/WIPS) to monitor for anomalous or suspicious wireless activity indicative of exploitation attempts. 5. Limit physical proximity access to wireless access points by securing device locations and restricting unauthorized personnel. 6. Regularly audit and inventory network devices to identify those using affected MediaTek chipsets and prioritize them for remediation. 7. Use network access control (NAC) to enforce authentication and authorization policies, mitigating risks from compromised devices. 8. Educate IT staff on the specifics of this vulnerability to ensure rapid response and incident handling if exploitation is suspected. 9. Consider temporary disabling or restricting vulnerable wireless interfaces where feasible until patches are applied. 10. Collaborate with vendors and security communities to stay informed about patch releases and emerging exploit reports.
Affected Countries
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Technical Details
- Data Version
- 5.1
- Assigner Short Name
- MediaTek
- Date Reserved
- 2024-11-01T01:21:50.383Z
- Cvss Version
- null
- State
- PUBLISHED
Threat ID: 68ee16307eab8b438c025d1c
Added to database: 10/14/2025, 9:21:52 AM
Last enriched: 10/14/2025, 9:41:19 AM
Last updated: 10/16/2025, 8:44:01 AM
Views: 7
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