CVE-2026-71912 in VigorAP
Summary
by MITRE • 08/24/2026
Multiple DrayTek VigorAP models contain a buffer overflow vulnerability in the apautotest function. The vulnerability is caused by missing length checks during memory copy operations involving the CMD6 field. A remote attacker can trigger this vulnerability via crafted input, causing a denial of service or potentially executing arbitrary commands. Exploitation requires valid administrative credentials for the device's web management interface.
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Analysis
by VulDB Data Team • 08/24/2026
The identified vulnerability resides within the apautotest function of multiple DrayTek VigorAP wireless access point models and represents a classic buffer overflow condition arising from insufficient input validation. Specifically, the flaw is triggered during memory copy operations involving the CMD6 field, where the application fails to verify that the length of incoming data fits within the allocated buffer boundaries. This lack of bounds checking allows an attacker to supply crafted input strings that exceed the expected size limits, thereby overwriting adjacent memory regions on the device's stack or heap. Such memory corruption is a critical security failure as it disrupts the normal flow of execution and can lead to arbitrary code execution if the attacker successfully controls the overwritten return addresses or function pointers within the affected process space.
From an operational perspective, this vulnerability poses significant risks to network infrastructure integrity. While exploitation requires valid administrative credentials for the device's web management interface, which limits the attack surface compared to unauthenticated remote exploits, it still presents a severe threat in scenarios where credential theft occurs via phishing, brute force attacks, or other lateral movement techniques within an internal network. A successful exploit can result in a complete denial of service by crashing the access point firmware, leading to loss of connectivity for all associated wireless clients. More critically, if the attacker achieves arbitrary code execution with sufficient privileges, they could gain full control over the device, potentially using it as a pivot point to launch further attacks against other systems on the local network or exfiltrate sensitive data traversing the access point.
This vulnerability aligns closely with Common Weakness Enumeration (CWE) category CWE-120, which describes buffer copy without checking size of input, and specifically relates to CWE-787, out-of-bounds write. In terms of tactical classification under the MITRE ATT&CK framework, this flaw facilitates initial access through compromised credentials followed by execution capabilities that may allow for privilege escalation or persistence mechanisms depending on the specific firmware version and configuration. The requirement for administrative authentication classifies this as a lower severity risk in public threat landscapes but remains high priority for internal security audits where insider threats or credential compromise are plausible vectors.
To mitigate this vulnerability, organizations should immediately apply vendor-provided firmware updates that patch the missing length checks within the apautotest function and related memory handling routines. Until patches are available, it is advisable to restrict access to the web management interface by limiting IP addresses allowed to connect via firewall rules or VLAN segmentation. Additionally, enforcing strong password policies and multi-factor authentication where supported can reduce the likelihood of credential compromise that precedes exploitation. Regular vulnerability scanning focused on network infrastructure devices should be conducted to identify unpatched instances across the enterprise environment.