Security readout for executives and security teams
Plain-English summary
This flaw can expose login credentials from a D-Link DIR-605 B2 router running firmware 2.01MT. Because CISA lists it in KEV, exploitation has been observed. The business risk is unauthorized access to router administration, which can enable network compromise or traffic manipulation.
Executive priority
Prioritize remediation for any reachable affected router. KEV status makes this more than a theoretical issue, while the missing vendor fix details mean teams should confirm support status quickly and replace unsupported devices where needed.
Technical view
CVE-2021-40655 is an information disclosure issue tied to improper authorization. The source description says an unauthenticated network attacker can obtain username and password data through the getcfg.php page on D-Link DIR-605 B2 firmware 2.01MT. CVSS is 7.5, confidentiality impact high.
Likely exposure
Exposure appears limited to D-Link DIR-605 B2 devices running firmware 2.01MT, especially where router management is reachable from untrusted networks. The structured affected-product fields are incomplete, so validate by model and firmware inventory rather than assuming broader D-Link exposure.
Exploitation context
CISA KEV status supports known exploitation. The provided sources do not establish current exploitation volume, targeting, or campaign details. Treat reachable affected devices as urgent, but do not infer additional affected models or exploit behavior from the bundle.
Researcher notes
The CVE record and bundled description identify the vulnerable model, firmware, impact, and endpoint, but affected CPE data is absent. Avoid extrapolating to other D-Link products. Use KEV only to support known exploitation, not campaign specifics.
Mitigation direction
- Check D-Link security guidance for fixed firmware, retirement, or replacement direction.
- Remove internet exposure for router administration interfaces.
- Restrict management access to trusted administrative networks only.
- Rotate router credentials after remediation or replacement.
- Replace unsupported affected devices if no vendor-supported fix exists.
Validation and detection
- Inventory D-Link DIR-605 B2 routers and record firmware versions.
- Identify devices running firmware 2.01MT.
- Confirm management interfaces are not exposed to the internet.
- Review access logs for unexpected administrative access where logs exist.
- Verify remediation by rechecking firmware, access controls, and credential rotation.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-863: Authorization and privilege behavior lookup
Authorization weaknesses can support privilege escalation and valid-account review, depending on exploit path. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-40655 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- Yes
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CISA KEV status
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.dlink.com/en/security-bulletin/CVE reference · x_refsource_MISC
- https://github.com/Ilovewomen/D-LINK-DIR-605/CVE reference · x_refsource_MISC
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-40655CVE reference · government-resource
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Incorrect Authorization
Incorrect Authorization represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.