DrayTek VigorSwitch G2540xs Authentication auth_set username/password command injection

Summaryinfo

A vulnerability labeled 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. This affects the function auth_set of the component Authentication. Such manipulation of the argument username/password leads to command injection. This vulnerability is traded as CVE-2026-71923. The attack may be launched remotely. There is no exploit available.

Detailsinfo

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. Affected by this issue is the function auth_set of the component Authentication. The manipulation of the argument username/password with an unknown input leads to a command injection vulnerability. Using CWE to declare the problem leads to 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. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Multiple DrayTek VigorSwitch models contain a command injection vulnerability in the auth_set 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 available at draytek.com. This vulnerability is handled as CVE-2026-71923 since 08/08/2026. The exploitation is known to be easy. The attack may be launched remotely. Additional levels of successful authentication are needed for exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 08/24/2026). This vulnerability is assigned to T1202 by the MITRE ATT&CK project.

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

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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

CPE 2.3info

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CPE 2.2info

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Entryinfo

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