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PatchSiren cyber security CVE debrief

CVE-2020-25506 D-Link CVE debrief

CVE-2020-25506 is a command injection vulnerability affecting the D-Link DNS-320 device. CISA added it to the Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03, which is a strong signal that the issue has been exploited in the wild. The supplied sources do not provide deeper technical detail, but the KEV listing means this should be treated as a high-priority remediation item for any organization still operating the affected device.

Vendor
D-Link
Product
DNS-320 Device
CVSS
Unknown
CISA KEV
Listed
Original CVE published
2021-11-03
Original CVE updated
2021-11-03
Advisory published
2021-11-03
Advisory updated
2021-11-03

Who should care

Organizations and individuals that still operate D-Link DNS-320 devices should treat this as urgent, especially if the device is internet-exposed, remotely managed, or part of a legacy storage deployment. Security and IT teams responsible for asset inventory, network segmentation, and patching should confirm whether any DNS-320 units remain in service.

Technical summary

The vulnerability is described in the supplied corpus as a command injection flaw in the D-Link DNS-320 device. The CISA KEV record lists the product as D-Link DNS-320 Device, confirms it as a known exploited vulnerability, and directs defenders to apply updates per vendor instructions. No CVSS score or additional exploit details are provided in the supplied sources.

Defensive priority

High. Because this vulnerability is included in CISA’s KEV catalog, defenders should assume active exploitation risk and prioritize remediation over routine maintenance. The CISA record gave a due date of 2022-05-03 for applying updates per vendor instructions, so any remaining exposure is overdue for action.

Recommended defensive actions

  • Identify whether any D-Link DNS-320 devices are present in your environment, including forgotten or segmented legacy networks.
  • Apply updates per the vendor’s instructions, as directed by CISA’s KEV record.
  • If the device cannot be updated or is no longer supported, isolate it from untrusted networks or replace it.
  • Restrict administrative access to trusted management networks only.
  • Review logs and network activity for unexpected or anomalous device behavior.
  • Remove or retire the device if it cannot be brought into a supported and securely managed state.

Evidence notes

The debrief is based only on the supplied CVE metadata, the CISA KEV source item, and the official resource links provided. The corpus confirms the vulnerability type, affected product, KEV status, and remediation guidance, but does not provide CVSS, exploit mechanics, or vendor advisory details beyond the KEV note.

Official resources

CVE-2020-25506 was published on 2021-11-03, and CISA added it to the Known Exploited Vulnerabilities catalog the same day in the supplied timeline.