CVE-2021-40655: Technical Deep-Dive (Auto Refreshed)

Generated on 2026-03-25T18:22:11.841Z. This file is automatically regenerated every 30 minutes by the CVE AI enrichment job using web sources (NVD, MITRE, CISA KEV, GitHub).

Executive Technical Summary

An informtion disclosure issue exists in D-LINK-DIR-605 B2 Firmware Version : 2.01MT. An attacker can obtain a user name and password by forging a post request to the / getcfg.php page

• Context preserved from previous revision: An informtion disclosure issue exists in D-LINK-DIR-605 B2 Firmware Version : 2.01MT. An attacker can obtain a user name and password by forging a post request to the / getcfg.php page Notes: Ostorlab KEV: One-command to detect most remotely known exploitable vulnerabilities. Sourced from CISA KEV, Google's Tsunami, Ostorlab's Asteroid and Bug Bounty programs.

Technical Details

• CVE: CVE-2021-40655
• KEV date added: 2024-05-16
• KEV due date: 2024-06-06
• NVD published: 2021-09-25
• NVD modified: 2025-11-10
• MITRE modified: 2025-10-21
• CVSS base score: 7.5
• CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
• CVSS exploitability score: 3.9
• CVSS impact score: 3.6
• Attack vector: Network
• Attack complexity: Low
• Privileges required: None
• User interaction: None
• Scope: Unchanged
• Confidentiality impact: High
• Integrity impact: None
• Availability impact: None

Versions and Products Impacted

• dlink / dir-605l firmware (versions: 2.01mt)
• n/a / n/a (versions: n/a)
• dlink / dir-605l_firmware (versions: 2.01mt)
• dlink / dir-605l (versions: b2)

Weakness Classification

• CWE-863

Repositories for Lab Validation (Public Examples)

• Ostorlab/KEV | stars: 608 | updated: 2026-03-23 | https://github.com/Ostorlab/KEV
  Notes: Ostorlab KEV: One-command to detect most remotely known exploitable vulnerabilities. Sourced from CISA KEV, Google's Tsunami, Ostorlab's Asteroid and Bug Bounty programs.

People and Organizations Mentioned

• mitre
• D-Link
• DIR-605 Router
• Ostorlab

Practical Defensive Validation (Authorized Only)

1. Use only isolated environments and systems you own or are explicitly authorized to test.
2. Snapshot infrastructure before validation and preserve baseline logs (EDR, SIEM, OS, app).
3. Inventory dlink / dir-605l firmware (versions: 2.01mt) assets and confirm exact vulnerable versions with automated checks.
4. Patch in staged environments and validate closure with scanners + service health checks.
5. Map detections to MITRE ATT&CK tactics relevant to your environment and tune alert quality.

References

• NVD record: https://nvd.nist.gov/vuln/detail/CVE-2021-40655
• MITRE CVE record: https://www.cve.org/CVERecord?id=CVE-2021-40655
• CISA KEV Catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• CISA KEV JSON feed: https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json
• KEV notes: https://legacy.us.dlink.com/pages/product.aspx?id=2b09e95d90ff4cb38830ecc04c89cee5; https://nvd.nist.gov/vuln/detail/CVE-2021-40655
• https://github.com/Ilovewomen/D-LINK-DIR-605/
• https://www.dlink.com/en/security-bulletin/
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-40655
• Repository example: https://github.com/Ostorlab/KEV

This content is for defensive security training and authorized validation only.