Executive brief
A vulnerability exists in the Totolink A8000RU wireless router, a device used to provide internet connectivity and network management for homes and small offices. An attacker can exploit this flaw to take complete control of the router by executing unauthorized system commands. This could lead to the interception of network traffic, theft of sensitive data, or a total disruption of internet services.
Technical details
An OS command injection vulnerability exists in the 'setIpQosRules' function within the '/cgi-bin/cstecgi.cgi' component of Totolink A8000RU firmware version 7.1cu.643_b20200521. The root cause is improper neutralization of the 'Comment' argument, which is passed to the 'Uci_Set_Str' function and subsequently executed via 'execv()' through the 'CsteSystem' function. A remote, unauthenticated attacker can exploit this by sending a specially crafted POST request containing shell metacharacters (e.g., backticks) in the JSON payload. Successful exploitation grants the attacker full system-level command execution on the device. Public exploit code (PoC) is available.
Affected products
- Totolink A8000RU 7.1cu.643_b20200521
Timeline
- 2026-05-25: disclosed: Public disclosure of the vulnerability and PoC.
- 2026-05-25: advisory: CVE-2026-9475 published.