How severe is CVE-2021-40655?

CVE-2021-40655 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-40655 being actively exploited?

Yes. CVE-2021-40655 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2024-05-16, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2021-40655?

CVE-2021-40655 affects Dlink Dir-605l Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-40655?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

Does CVE-2021-40655 have an EU (EUVD) identifier?

Yes. CVE-2021-40655 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-27829. It is also flagged as exploited in the EUVD (since 2024-05-16).

When was CVE-2021-40655 published?

CVE-2021-40655 was published on 2021-09-24 and last updated on 2026-06-17.

CVE-2021-40655

CVE-2021-40655 is a high-severity vulnerability in Dlink Dir-605l Firmware with a CVSS 3.x base score of 7.5. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2024-05-16). The underlying weakness is classified as CWE-863.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 87% (100th percentile)
Actively exploited: Yes — listed in CISA KEV (added 2024-05-16)
EU (EUVD) id: EUVD-2021-27829
EU exploitation: Flagged exploited in the ENISA EU Vulnerability Database (since 2024-05-16)
Weakness: CWE-863
Affected product: Dlink Dir-605l Firmware
Published: 2021-09-24
Last modified: 2026-06-17

Description

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

Frequently asked questions

What is CVE-2021-40655?: 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
How severe is CVE-2021-40655?: CVE-2021-40655 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-40655 being actively exploited?: Yes. CVE-2021-40655 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2024-05-16, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2021-40655?: CVE-2021-40655 affects Dlink Dir-605l Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-40655?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
Does CVE-2021-40655 have an EU (EUVD) identifier?: Yes. CVE-2021-40655 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-27829. It is also flagged as exploited in the EUVD (since 2024-05-16).
When was CVE-2021-40655 published?: CVE-2021-40655 was published on 2021-09-24 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:dlink:dir-605l_firmware:2.01mt:*:*:*:*:*:*:*

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