Executive brief
DrayTek VigorSwitch is a managed network switch used in enterprise and carrier networks. A pre-authentication null pointer dereference in the web management interface (setget.cgi component) allows a remote attacker to crash the device and disrupt network operations by sending a specially crafted request, causing temporary service unavailability.
Technical details
The vulnerability is a null pointer dereference (CWE-476) in the setget.cgi web interface component, triggered by missing validation of the pass (password) field when it is absent from requests. The vulnerability is pre-authentication, meaning no credentials are required to trigger it. A remote attacker can send a crafted HTTP request to the web management interface without authentication to cause the process to crash, resulting in a denial of service. Patches are available; affected devices should be updated to the vendor-specified firmware versions listed in the DrayTek security advisory DSA-2026-003.
Affected products
- DrayTek VigorSwitch G2540xs before 3.9.10
- DrayTek VigorSwitch P2540xs before 3.9.10
- DrayTek VigorSwitch FX2120 before 3.9.10
- DrayTek VigorSwitch G2282x before 2.10.6
- DrayTek VigorSwitch P2282x before 2.10.6
- DrayTek VigorSwitch Q2300x before 2.10.7
- DrayTek VigorSwitch PQ2300xb before 2.10.7
- DrayTek VigorSwitch G2542x before 3.10.6
- DrayTek VigorSwitch P2542x before 3.10.6
- DrayTek VigorSwitch P2542xh before 3.10.6
- DrayTek VigorSwitch PX2060 before 2.9.10
- DrayTek VigorSwitch G1280 before 2.9.10
- DrayTek VigorSwitch P1280 before 2.9.10
- DrayTek VigorSwitch P1281x before 2.9.10
- DrayTek VigorSwitch G1282 before 2.9.10
- DrayTek VigorSwitch P1282 before 2.9.10
- DrayTek VigorSwitch G2121 before 2.9.10
- DrayTek VigorSwitch P2121 before 2.9.10
- DrayTek VigorSwitch PQ2121x before 2.9.10
- DrayTek VigorSwitch Q2121x before 2.9.10
- DrayTek VigorSwitch G2280x before 2.9.10
- DrayTek VigorSwitch P2280x before 2.9.10
- DrayTek VigorSwitch Q2200x before 2.9.10
- DrayTek VigorSwitch PQ2200xb before 2.9.10
- DrayTek VigorSwitch G2100 before 2.9.10
- DrayTek VigorSwitch P2100 before 2.9.10
- DrayTek VigorSwitch G2540x before 2.9.10
- DrayTek VigorSwitch P2540x before 2.9.10
Timeline
- 2026-08-24: disclosed
- 2026-08-24: patched: Multiple firmware versions released