HOMEVULNERABILITIESCVE-2021-20697
CRITICAL

CVE-2021-20697

CWE-306Published: April 26, 2021· Updated: Jun 17, 2026

9.8
CVSS v3.1

Official Description

Missing authentication for critical function in DAP-1880AC firmware version 1.21 and earlier allows a remote attacker to login to the device as an authenticated user without the access privilege via unspecified vectors.

NVD Source

Technical Analysis

CVE-2021-20697 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

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 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

dlink2 product(s)
dap-1880ac firmwaredap-1880ac
Source: NVD CPE · 2 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://jvn.jp/en/vu/JVNVU92898656/index.html
ADVISORYhttps://www.dlink-jp.com/support/release/jvnvu92898656_dap-1880ac.html
ADVISORYhttps://jvn.jp/en/vu/JVNVU92898656/index.html
ADVISORYhttps://www.dlink-jp.com/support/release/jvnvu92898656_dap-1880ac.html

All References (4)

→
https://jvn.jp/en/vu/JVNVU92898656/index.htmlThird Party Advisory
→
https://www.dlink-jp.com/support/release/jvnvu92898656_dap-1880ac.htmlVendor Advisory
→
https://jvn.jp/en/vu/JVNVU92898656/index.htmlThird Party Advisory
→
https://www.dlink-jp.com/support/release/jvnvu92898656_dap-1880ac.htmlVendor Advisory

Quick Facts

CVE IDCVE-2021-20697
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-306
CISA KEVNo
Affected1 vendor(s)
PublishedApr 26, 2021

Related CVEs (CWE-306)

CVE-2026-2577
10.0
CVE-2007-0956
10.0
CVE-2026-34162
10.0
CVE-2023-48426
10.0
CVE-2026-49257
10.0
CVE-2019-11061
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-20697 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. CVE data is provided under the NVD usage policy.
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