CVE-2021-36706: In ProLink PRC2402M V1.0.18 and older, the set_sys_cmd function in the adm.cgi binary, accessible with a page

Q: How do I fix CVE-2021-36706?

prc2402m firmware: upgrade to newer than 1.0.18. Exact commands for each OS are on this page.

Q: Is CVE-2021-36706 being exploited?

CVE-2021-36706 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-36706 affect?

CVE-2021-36706 affects prc2402m firmware. Severity is critical (CVSS 9.8). In ProLink PRC2402M V1.0.18 and older, the set_sys_cmd function in the adm.cgi binary, accessible with a page parameter value of sysCMD contains a trivial command injection where the value of the command parameter is passed directly to syst

Q: How urgent is CVE-2021-36706?

Priority 66/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

CRITICAL 9.8REMOTEUPGRADE

CVE-2021-36706 is a critical-severity flaw (CVSS 9.8) affecting prc2402m firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In ProLink PRC2402M V1.0.18 and older, the set_sys_cmd function in the adm.cgi binary, accessible with a page parameter value of sysCMD contains a trivial command injection where the value of the command parameter is passed directly to system.

Why this priority

Critical severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	2.6% (top 15%)
CISA exploited list	No
Weakness	CWE-78
Published	2021-08-06
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: prolink

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-08-06 14:15 UTCPublished CVE record published
2026-06-17 03:59 UTCUpdated Record last modified

prolink prc2402m firmware UPGRADE

Affected: <= 1.0.18

Fixed in: newer than 1.0.18

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-36706?

prc2402m firmware: upgrade to newer than 1.0.18. Exact commands for each OS are on this page.

Is CVE-2021-36706 being exploited?

CVE-2021-36706 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-36706 affect?

CVE-2021-36706 affects prc2402m firmware. Severity is critical (CVSS 9.8). In ProLink PRC2402M V1.0.18 and older, the set_sys_cmd function in the adm.cgi binary, accessible with a page parameter value of sysCMD contains a trivial command injection where the value of the command parameter is passed directly to syst

How urgent is CVE-2021-36706?

Priority 66/100. Critical severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2021-36708 HIGH 7.5 UPGRADE In ProLink PRC2402M V1.0.18 and older, the set_sys_init function in the login.cgi binary allows an attacker to
CVE-2021-36707 CRITICAL 9.8 UPGRADE In ProLink PRC2402M V1.0.18 and older, the set_ledonoff function in the adm.cgi binary, accessible with a page
CVE-2021-36705 CRITICAL 9.8 UPGRADE In ProLink PRC2402M V1.0.18 and older, the set_TR069 function in the adm.cgi binary, accessible with a page pa

References

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