Predictive Vulnerability Intelligence.

Product

  • Product
  • Pricing
  • Documentation

Company

  • About
  • Partnerships
  • Blog
  • Support

Legal

  • Terms
  • Privacy
  • Data Licensing

© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2021-21820

32
FAUCET Score

CVE-2021-21820 is a critical hard-coded password vulnerability in the Libcli Test Environment of D-Link DIR-3040 1.13B03 routers, allowing unauthenticated attackers to achieve remote code execution through specially crafted network requests. With a CVSS score of 9.8, this vulnerability is easily exploitable over the network with low attack complexity, leading to complete compromise of confidentiality, integrity, and availability. While there is no evidence of active exploitation or public exploit code in Metasploit, Nuclei, or ExploitDB, the vulnerability has garnered significant community attention with 11 mentions and media coverage, indicating awareness and potential future exploitation. D-Link has released a hotfix to address this issue.

Impacted Technologies

VendorProductVersion(s)CPE
1.13b03CPE matchmatch criteria
cpe:2.3:o:dlink:dir-3040_firmware:1.13b03:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.0

10.0CRITICAL

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
Exploitability Score
3.9
Impact Score
6.0
CvssVersion
3.0

Exploit Intelligence

EPSS Score
2.96%
Probability of exploitation in next 30 days
EPSS Percentile
85.8%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0296 is in the 77th percentile among its peer group of 36,897 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.3 Bluesky, 0.3 Mastodon, and 2.4 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.3 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

talosintelligence.com / vulnerability_reports/TALOS-2021-1285
ExploitThird Party Advisory