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CVE-2021-39509

CRITICAL
9.8
CVSS Score
Published: August 24, 2021 at 06:52 PM UTC
Updated: June 17, 2026 at 04:03 AM UTC
2 products affected across 1 vendorDir 816 FirmwareDir-816

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Severity
CRITICAL9.8
Exploit prediction
EPSS 5%

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Dir 816 Firmware· D-Link
95%
1.10cnb05_r1b011d88210
dlink-dir-816 (same device)
Dir-816· D-Linkdevice
80%
All versions

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

Patch and advisory references

References (3)

x_refsource_MISCThird Party Advisory
Source: [email protected]
https://github.com/doudoudedi/main-DIR-816_A2_Command-injection
x_refsource_MISCExploitThird Party Advisory
Source: [email protected]
https://github.com/doudoudedi/main-DIR-816_A2_Command-injection/blob/main/injection.md
x_refsource_MISCVendor Advisory
Source: [email protected]
https://www.dlink.com/en/security-bulletin/

CVSS

9.8CRITICAL[email protected]
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-77

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