CVE-2021-40655: in the CISA KEV catalogue

D-Link DIR-605 Router Information Disclosure Vulnerability. CISA added CVE-2021-40655 to the Known Exploited Vulnerabilities catalogue on 2024-05-16 with a default due date of 2024-06-06. Known ransomware campaign use: Unknown. Forensic triage flag: No.

D-Link DIR-605 routers contain an information disclosure vulnerability that allows attackers to obtain a username and password by forging a post request to the /getcfg.php page. (CISA description)

Vendor / product: D-Link DIR-605 Router
CWE: CWE-863
CISA required action: This vulnerability affects legacy D-Link products. All associated hardware revisions have reached their end-of-life (EOL) or end-of-service (EOS) life cycle and should be retired and replaced per vendor instructions.
EPSS: 87%, percentile 99 (scored 2026-11-03)

EPSS puts about 87 in 100 odds (87%) on exploitation activity being observed in the next 30 days. Its score is higher than or equal to that of 99% of scored CVEs. This is a model estimate about exploitation anywhere, not about your environment.

Vendor and reference links (from CISA)

Your own deadline under CISA BOD 26-04 depends on exposure, automatability and technical impact: work it out with the BOD 26-04 calculator.

Data dates. CISA KEV catalogue version 2026.11.03, released 2026-11-03, 1,767 entries (checked 2026-11-03). EPSS model v2026.06.15, scored 2026-11-03, 399,388 CVEs. Sources: CISA and FIRST (EPSS by FIRST; scores generated by Empirical Security). Copied to our own database and refreshed automatically; if a refresh fails, the previous copy keeps serving with its own date.

Frequently asked questions

Is CVE-2021-40655 in the CISA KEV catalogue?

Yes. CISA added CVE-2021-40655 (D-Link DIR-605 Router Information Disclosure Vulnerability) to the Known Exploited Vulnerabilities catalogue on 2024-05-16. CISA's default due date for it is 2024-06-06.

Is CVE-2021-40655 used in ransomware attacks?

CISA marks known ransomware campaign use as Unknown for CVE-2021-40655. That means CISA lacks confirmation, not that ransomware groups do not use it.

What should I do about CVE-2021-40655?

CISA's required action: This vulnerability affects legacy D-Link products. All associated hardware revisions have reached their end-of-life (EOL) or end-of-service (EOS) life cycle and should be retired and replaced per vendor instructions.

Sources

CISA, Known Exploited Vulnerabilities Catalog (accessed 2026-11-03)
FIRST, Exploit Prediction Scoring System (EPSS) (EPSS by FIRST; scores generated by Empirical Security)
NVD record for CVE-2021-40655