CVE-2021-3708Public exploit

Root command execution via unsanitized MAC address

Published Aug 16, 2021 · Updated Aug 3, 2024

OS command injection in D-Link DSL-2750U firmware vME1.16 and earlier allows remote attackers on the local network to execute OS commands. The webupg CGI MAC-address handler places unsanitized input into an echo command and passes it to system(), while the mini_httpd service runs as root. Exploitation requires the configuration-access chain described with CVE-2021-3707; successful commands therefore execute with root privileges on the router.

CVSS severity7.8
High
EPSS probability24.56%
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 DSL-2750U firmware vME1.16 and earlier allows remote attackers on the local network to execute OS commands. The webupg CGI MAC-address handler places unsanitized input into an echo command and passes it to system(), while the mini_httpd service runs as root. Exploitation requires the configuration-access chain described with CVE-2021-3707; successful commands therefore execute with root privileges on the router.

The record

CVE
CVE-2021-3708
Published
Aug 16, 2021
Updated
Aug 3, 2024
Vendor
D-Link
Product
DSL-2750U
Classifications
CWE-78, T1059
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 16, 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=firmware vME1.16 or prior versions

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

D-Link · DSL-2750Uversion=firmware vME1.16 or prior versions

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.2NVDAV:L/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 exploitPublished

Weakness, pattern, technique

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

Public exploit references

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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