dbcve.org
Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 3 May 2022.
Dir 825 R1 FirmwareOperating system · Dlink

CVE-2020-29557

CRITICAL · 9.8 CVSS v3.1 Published 2021-01-29
Fix available
A fix is available. Upgrade to after 3.0.1 or later.
See remediation →
100/100
Remediation priority · Urgent
In the wild High EPSS Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
An issue was discovered on D-Link DIR-825 R1 devices through 3.0.1 before 2020-11-20. A buffer overflow in the web interface allows attackers to achieve pre-authentication remote code execution.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A buffer overflow vulnerability exists in the web interface of D-Link DIR-825 R1 routers running firmware versions 3.0.1 and earlier, released prior to November 2020. The flaw allows remote attackers to achieve pre-authentication remote code execution due to insufficient bounds checking in the web component.

MitigationApply the vendor firmware update released after November 2020 to patch the buffer overflow vulnerability. If updating is not possible, restrict web interface access to trusted networks or disable remote management.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Dir 825 R1 FirmwareOperating system
Affected:<= 3.0.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the device model
    Locate the model number on the device label or check the web interface status page for 'DIR-825' and confirm it is revision R1
    Affected if The device is not a D-Link DIR-825 R1
  2. Determine the installed firmware version
    Access the router web interface, navigate to the Status or System section, and locate the firmware version displayed (commonly at the bottom of status pages)
    Affected if The firmware version is 3.0.1 or lower
  3. Verify the web management interface is enabled
    Check the router web interface under Setup or Administration settings for 'Web Management' or 'HTTP/HTTPS Management' access options
    Affected if The web interface is enabled and accessible
  4. Assess network exposure
    Determine if the router's web interface is reachable from the internet by attempting to access the device's WAN IP on ports 80/443, or by reviewing firewall/NAT rules
    Affected if The web management interface is exposed to untrusted networks (internet-facing)

You are affected if you have a D-Link DIR-825 R1 router running firmware version 3.0.1 or lower with the web interface enabled and accessible, especially if it is internet-facing.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 3.0.1
Interim mitigation

Apply the vendor firmware update released after November 2020 to patch the buffer overflow vulnerability. If updating is not possible, restrict web interface access to trusted networks or disable remote management.

Recommended fix Moderate confidence

Any firmware version released after November 2020 (check D-Link support for the specific version number)

  1. 1. Visit the official D-Link support page for the DIR-825 R1 device
  2. 2. Navigate to the firmware download section
  3. 3. Download the latest firmware version released after November 2020
  4. 4. Access the router's web interface via its IP address (typically 192.168.0.1)
  5. 5. Navigate to the 'System' or 'Management' section
  6. 6. Select 'Firmware Upgrade' or 'Router Update'
  7. 7. Upload the downloaded firmware file and wait for the upgrade to complete
  8. 8. After reboot, verify the firmware version in the router settings
Caveat Minor: Router will reboot during upgrade; ensure stable power connection

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Dir 825 R1 Firmware Exploited in the wild — priority engagement
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
4.0 hours of engineering $750
Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,200.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2020-29557 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-29557 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data