VU#677427: D-Link routers HNAP service contains stack-based buffer overflow

Vulnerability Note VU#677427

D-Link routers HNAP service contains stack-based buffer overflow

Original Release date: 07 Nov 2016 | Last revised: 10 Nov 2016


D-Link DIR routers contain a stack-based buffer overflow in the HNAP Login action.


CWE-121: Stack-based Buffer Overflow – CVE-2016-6563

Processing malformed SOAP messages when performing the HNAP Login action causes a buffer overflow in the stack. The vulnerable XML fields within the SOAP body are: Action, Username, LoginPassword, and Captcha.

CVE-2016-6563 appears to affect:

  • DIR-823
  • DIR-822
  • DIR-818L(W)
  • DIR-895L
  • DIR-890L
  • DIR-885L
  • DIR-880L
  • DIR-868L


A remote, unauthenticated attacker may be able to execute arbitrary code with root privileges.


Apply an update

D-Link has released firmware updates to address the vulnerabilities in affected routers. Please see their announcement.
If you are unable to update your device, please see the following workarounds:

Restrict Access

As a general good security practice, only allow connections from trusted hosts and networks. Additionally, you may wish to disable remote administration of the router.

Vendor Information (Learn More)

Vendor Status Date Notified Date Updated
D-Link Systems, Inc. Affected 12 Sep 2016 27 Oct 2016

If you are a vendor and your product is affected, let
us know

CVSS Metrics (Learn More)

Group Score Vector
Base 9.3 AV:N/AC:M/Au:N/C:C/I:C/A:C
Temporal 8.0 E:POC/RL:W/RC:ND
Environmental 6.0 CDP:N/TD:M/CR:ND/IR:ND/AR:ND



Thanks to Pedro Ribeiro ( of Agile Information Security for reporting this vulnerability.

This document was written by Trent Novelly.

Other Information

  • CVE IDs:
  • Date Public:
    07 Nov 2016
  • Date First Published:
    07 Nov 2016
  • Date Last Updated:
    10 Nov 2016
  • Document Revision:


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