The executable httpd on the TP-Link WR841N V8 router before TL-WR841N(UN)_V8_170210 contained a design flaw in the use of DES for block encryption. This resulted in incorrect access control, which allowed attackers to gain read-write access to system settings through the protected router configuration service tddp via the LAN and Ath0 (Wi-Fi) interfaces.
Severity
CVSS 3.0
9.8 critical
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
0.5% chance of exploitation in the next 30 days; higher than 42% of CVEs (scores of 2026-10-31)