Overview

In November 28, 2018, D-Link becamea aware of a 3rd Party security researcher that accused the DCS-5020L Hardware Rev. Ax of a command injection vulnerability in the web-GUI.

After an investigation, this vulnerability is only accessable via the local-network since the cameras Web-GUI only responds on the same subnet was the PC Host web-browser. and not directly from the internet (WAN-side))

3rd Party Report:

Evan Walls :: Link to Contact

• CVE-2019-10999 :: https://nvd.nist.gov/vuln/detail/CVE-2019-10999
• Github :: https://github.com/fuzzywalls/CVE-2019-10999
• Onward Security :: http://www.cnnvd.org.cn/web/xxk/ldxqById.tag?CNNVD=CNNVD-201905-138
• Author Post Part 1 :: https://www.refirmlabs.com/d-link-a-firmware-vulnerability-part-1/
• Author Post Part 2 :: https://www.refirmlabs.com/d-link-a-firmware-vulnerability-part-2/

Details

Note: The exploit requires credentials to be successful.

There exists an authenticated buffer overflow vulnerability in the accused cameras  that can be exploited by malicious users. It occurs when a large string is passed in the WEPEncryption parameter provided to wireless.htm. The variable is expected to be a single character of some value between 0 and 4 based on radio buttons selected by the user. Because of this assumption the length of the string is never verified and passed directly to strcpy() which copies directly to a stack variable. This overwrite can be used to gain control of the return address and possible to execute arbitrary code.
 

Affected Products and Fixes: