DrayTek VigorSwitch G2540xs setDevNet username/password command injection

Summaryinfo

A vulnerability was found in DrayTek VigorSwitch G2540xs, VigorSwitch P2540xs, VigorSwitch FX2120, VigorSwitch G2282x, VigorSwitch P2282x, VigorSwitch Q2300x, VigorSwitch PQ2300xb, VigorSwitch G2542x, VigorSwitch P2542x, VigorSwitch P2542xh, VigorSwitch PX2060, VigorSwitch G1280, VigorSwitch P1280, VigorSwitch P1281x, VigorSwitch G1282, VigorSwitch P1282, VigorSwitch G2121, VigorSwitch P2121, VigorSwitch PQ2121x, VigorSwitch Q2121x, VigorSwitch G2280x, VigorSwitch P2280x, VigorSwitch Q2200x, VigorSwitch PQ2200xb, VigorSwitch G2100, VigorSwitch P2100, VigorSwitch G2540x and VigorSwitch P2540x and classified as very critical. This affects the function setDevNet. The manipulation of the argument username/password results in command injection. This vulnerability is identified as CVE-2026-71943. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability classified as very critical has been found in DrayTek VigorSwitch G2540xs, VigorSwitch P2540xs, VigorSwitch FX2120, VigorSwitch G2282x, VigorSwitch P2282x, VigorSwitch Q2300x, VigorSwitch PQ2300xb, VigorSwitch G2542x, VigorSwitch P2542x, VigorSwitch P2542xh, VigorSwitch PX2060, VigorSwitch G1280, VigorSwitch P1280, VigorSwitch P1281x, VigorSwitch G1282, VigorSwitch P1282, VigorSwitch G2121, VigorSwitch P2121, VigorSwitch PQ2121x, VigorSwitch Q2121x, VigorSwitch G2280x, VigorSwitch P2280x, VigorSwitch Q2200x, VigorSwitch PQ2200xb, VigorSwitch G2100, VigorSwitch P2100, VigorSwitch G2540x and VigorSwitch P2540x. Affected is the function setDevNet. The manipulation of the argument username/password with an unknown input leads to a command injection vulnerability. CWE is classifying the issue as CWE-77. The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when it is sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

Multiple DrayTek VigorSwitch models contain a command injection vulnerability in the setDevNet function. The vulnerability is caused by insufficient filtering of the username and password fields before command execution. A remote attacker can trigger this vulnerability via crafted input to execute arbitrary commands with root privileges. Exploitation requires valid administrative credentials for the device's web management interface.

The advisory is shared for download at draytek.com. This vulnerability is traded as CVE-2026-71943 since 08/08/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation needs additional levels of successful authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/24/2026). The MITRE ATT&CK project declares the attack technique as T1202.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Router Operating System

Vendor

• DrayTek

Name

• VigorSwitch FX2120
• VigorSwitch G1280
• VigorSwitch G1282
• VigorSwitch G2100
• VigorSwitch G2121
• VigorSwitch G2280x
• VigorSwitch G2282x
• VigorSwitch G2540x
• VigorSwitch G2540xs
• VigorSwitch G2542x
• VigorSwitch P1280
• VigorSwitch P1281x
• VigorSwitch P1282
• VigorSwitch P2100
• VigorSwitch P2121
• VigorSwitch P2280x
• VigorSwitch P2282x
• VigorSwitch P2540x
• VigorSwitch P2540xs
• VigorSwitch P2542x
• VigorSwitch P2542xh
• VigorSwitch PQ2121x
• VigorSwitch PQ2200xb
• VigorSwitch PQ2300xb
• VigorSwitch PX2060
• VigorSwitch Q2121x
• VigorSwitch Q2200x
• VigorSwitch Q2300x

License

• commercial

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Entryinfo

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