CVE-2026-71935

Multiple DrayTek VigorSwitch models contain a buffer overflow vulnerability in the webBackupAction function. The vulnerability is caused by repeated string concatenation of the pathN, valueN, key, and option fields into fixed-size stack buffers without total length checks. 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.

CVSS v3 7.2 HIGH

7.2^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.2 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required HIGH

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://www.draytek.com/about/security-advisory/multiple-vulnerabilities-in-vigorswitch-series-august-2026/
https://www.vulncheck.com/advisories/draytek-vigorswitch-multiple-models-buffer-overflow-via-webbackupaction

Configurations

No configuration.

History

12 Oct 2026, 22:10

Type	Values Removed	Values Added
Summary		(es) Múltiples modelos DrayTek VigorSwitch contienen una vulnerabilidad de desbordamiento de búfer en la función webBackupAction. La vulnerabilidad es causada por la concatenación repetida de cadenas de los campos pathN, valueN, key y option en búferes de pila de tamaño fijo sin comprobaciones de longitud total. Un atacante remoto puede activar esta vulnerabilidad a través de una entrada manipulada, causando una denegación de servicio o potencialmente ejecutando comandos arbitrarios. La explotación requiere credenciales administrativas válidas para la interfaz de gestión web del dispositivo.

Information

Published : 2026-08-24 18:17

Updated : 2026-10-12 22:10

NVD link : CVE-2026-71935

Mitre link : CVE-2026-71935

CVE.ORG link : CVE-2026-71935

JSON object : View

Products Affected

No product.

CWE

CWE-120

Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

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The vulnerability is caused by repeated string concatenation of the pathN, valueN, key, and option fields into fixed-size stack buffers without total length checks. 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."}, {"lang": "es", "value": "M\u00faltiples modelos DrayTek VigorSwitch contienen una vulnerabilidad de desbordamiento de b\u00fafer en la funci\u00f3n webBackupAction. La vulnerabilidad es causada por la concatenaci\u00f3n repetida de cadenas de los campos pathN, valueN, key y option en b\u00faferes de pila de tama\u00f1o fijo sin comprobaciones de longitud total. Un atacante remoto puede activar esta vulnerabilidad a trav\u00e9s de una entrada manipulada, causando una denegaci\u00f3n de servicio o potencialmente ejecutando comandos arbitrarios. La explotaci\u00f3n requiere credenciales administrativas v\u00e1lidas para la interfaz de gesti\u00f3n web del dispositivo."}], "lastModified": "2026-10-12T22:10:00.247", "sourceIdentifier": "disclosure@vulncheck.com"}