Advisory Details

November 26th, 2019

TP-LINK TL-WR841N Web Service http_parser_main Buffer Overflow Remote Code Execution Vulnerability

ZDI-19-992
ZDI-CAN-8457

CVE ID CVE-2019-17147
CVSS SCORE 8.8, (AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
AFFECTED VENDORS TP-Link
AFFECTED PRODUCTS TL-WR841N
VULNERABILITY DETAILS

This vulnerability allows remote attackers to execute arbitrary code on affected installations of TP-LINK TL-WR841N routers. Authentication is not required to exploit this vulnerability.

The specific flaw exists within the web service, which listens on TCP port 80 by default. When parsing the Host request header, the process does not properly validate the length of user-supplied data prior to copying it to a fixed-length static buffer. An attacker can leverage this vulnerability to execute code in the context of the admin user.

ADDITIONAL DETAILS TP-Link has issued an update to correct this vulnerability. More details can be found at:
https://www.tp-link.com/us/support/download/tl-wr841n/#Firmware
DISCLOSURE TIMELINE
  • 2019-07-04 - Vulnerability reported to vendor
  • 2019-11-26 - Coordinated public release of advisory
CREDIT Nguyen Hoang Thach - Security Researcher at VNPT ISC
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