CVE-2021-27249

Root code execution via WEB_CmdFileList command injection

Published Apr 14, 2021 · Updated Aug 3, 2024

OS command injection in D-Link DAP-2020 firmware 1.01rc001 allows network-adjacent attackers to execute arbitrary code as root. The WEB_CmdFileList CGI handler passes an unvalidated user-supplied string into a system call, permitting injected operating-system commands. Exploitation requires access to an adjacent wired or wireless network but no authentication or user interaction, and successful commands run with full device control.

CVSS severity8.8
High
EPSS probability5.09%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in D-Link DAP-2020 firmware 1.01rc001 allows network-adjacent attackers to execute arbitrary code as root. The WEB_CmdFileList CGI handler passes an unvalidated user-supplied string into a system call, permitting injected operating-system commands. Exploitation requires access to an adjacent wired or wireless network but no authentication or user interaction, and successful commands run with full device control.

The record

CVE
CVE-2021-27249
Published
Apr 14, 2021
Updated
Aug 3, 2024
Vendor
D-Link
Product
DAP-2020
Classifications
CWE-78, T1059
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 14, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=v1.01rc001

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

D-Link · DAP-2020version=v1.01rc001

Published CVSS scores

8.8Zero Day InitiativeCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.8NIST NVDCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
8.3NIST NVDAV:A/AC:L/Au:N/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059Command and Scripting Interpreter

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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