HOMEVULNERABILITIESCVE-2021-20709
HIGH

CVE-2021-20709

CWE-354Published: April 26, 2021· Updated: Jun 17, 2026

7.2
CVSS v3.1

Official Description

Improper validation of integrity check value vulnerability in NEC Aterm WF1200CR firmware Ver1.3.2 and earlier, Aterm WG1200CR firmware Ver1.3.3 and earlier, and Aterm WG2600HS firmware Ver1.5.1 and earlier allows an attacker with an administrative privilege to execute arbitrary OS commands by sending a specially crafted request to a specific URL.

NVD Source

Technical Analysis

CVE-2021-20709 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires high privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.2.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.High
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

nec6 product(s)
aterm wf1200cr firmwareaterm wf1200craterm wg1200cr firmwareaterm wg1200craterm wg2600hs firmwareaterm wg2600hs
Source: NVD CPE · 6 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

ADVISORYhttps://jpn.nec.com/security-info/secinfo/nv21-010.html
ADVISORYhttps://jvn.jp/en/jp/JVN29739718/index.html
ADVISORYhttps://jpn.nec.com/security-info/secinfo/nv21-010.html
ADVISORYhttps://jvn.jp/en/jp/JVN29739718/index.html

All References (4)

→
https://jpn.nec.com/security-info/secinfo/nv21-010.htmlMitigation · Vendor Advisory
→
https://jvn.jp/en/jp/JVN29739718/index.htmlThird Party Advisory
→
https://jpn.nec.com/security-info/secinfo/nv21-010.htmlMitigation · Vendor Advisory
→
https://jvn.jp/en/jp/JVN29739718/index.htmlThird Party Advisory

Quick Facts

CVE IDCVE-2021-20709
CVSS Score7.2 / 10
SeverityHIGH
WeaknessCWE-354
CISA KEVNo
Affected1 vendor(s)
PublishedApr 26, 2021

Related CVEs (CWE-354)

CVE-2023-33668
9.8
CVE-2023-28386
9.8
CVE-2017-15994
9.8
CVE-2026-32105
9.3
CVE-2025-54887
9.1
CVE-2022-29898
9.1

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-20709 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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