Vulnerability record

CVE-2021-39509

A permanent, source-backed tracker page. Values are shown only when returned; explicit gaps and read failures remain different states.

Full record read. Reported values and explicit gaps below come from the tracked record. Tracker snapshot: Aug 8, 2026.

What it is

Reported

An issue was discovered in D-Link DIR-816 DIR-816A2_FWv1.10CNB05_R1B011D88210 The HTTP request parameter is used in the handler function of /goform/form2userconfig.cgi route, which can construct the user name string to delete the user function. This can lead to command injection through shell metacharacters. Source description excerpt; complete tracked detail loads below.

NVD published: Aug 24, 2021 · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

What is affected

Reported

D-Link — dir-816_firmware. Product-level identification only; no affected-version conclusion is available from this field.

NVD published: Aug 24, 2021 · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

Urgency and basis

Reported

Act · 456.7

Tracker decision tier from the evidence detailed below · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

Exploitation evidence

Reported

kev-listed · VulnCheck KEV

VulnCheck KEV added: Oct 9, 2024 · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

What to do

Reported

Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Source remediation ↗

Tracked source remediation field · Source record updated: Aug 8, 2026 · Tracker snapshot: Aug 8, 2026

Evidence detail

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