Submit #754640: Tenda A21 V1.0.0.0 Stack-based Buffer Overflowinfo

TitleTenda A21 V1.0.0.0 Stack-based Buffer Overflow
DescriptionDuring a security review of the Tenda A21 router firmware (version V1.0.0.0), a critical stack-based buffer overflow vulnerability was identified in the device name configuration endpoint /goform/SetOnlineDevName. The vulnerability exists in the set_device_name function, which is invoked by the formSetDeviceName handler. The handler retrieves the user-controlled devName parameter and passes it to set_device_name. Inside this function, the input string is directly used in an unsafe sprintf call to format a string into a fixed-size stack buffer s__1[256]. The code fails to validate the length of the input string before this operation.
Source⚠️ https://github.com/QIU-DIE/cve-nneeww/issues/6
User
 hhsw34 (UID 91076)
Submission02/09/2026 13:04 (3 months ago)
Moderation02/20/2026 18:04 (11 days later)
StatusAccepted
VulDB entry347180 [Tenda A21 1.0.0.0 /goform/SetOnlineDevName set_device_name devName stack-based overflow]
Points20

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