A serious zero-day vulnerability has been found in TP-Link Archer, Deco, and Tapo routers, which could let attackers inject harmful commands and take full control of the devices.
This vulnerability affects both old and recent firmware versions of popular router models, raising serious security concerns for users until November 4, 2024.
The vulnerability was first found in an old firmware version of the AXE75 router from 2023, but later investigations showed it also exists in the latest firmware.
Security researchers used different methods to study and take advantage of this weakness:
Firmware Acquisition: TP-Link’s firmware is openly accessible and not protected, making it easier to analyze than those of other vendors.
Reverse Engineering: By using tools such as binwalk, researchers uncovered the firmware’s contents, revealing the router’s file system structure and key components.
Emulation: The router’s web interface was simulated using “qemu-arm-static,” allowing for targeted vulnerability assessment without physical hardware.
Vulnerability Identification: Researchers found security vulnerabilities by examining specific functions in Lua scripts. A major flaw was identified in the avira.lua file, which is part of the Avira antivirus software meant to protect devices.
ThottySploity researchers found a vulnerability in the “tmp_get_sites” function, where the ownerId variable is sent to the os.execute function without adequate sanitization or validation.
Exploitation:
Researchers developed an exploit that targets the vulnerability through the “/admin/smart_network” endpoint.
Attackers can exploit the ownerId parameter to execute malicious commands with root privileges on routers, leading to the potential theft of sensitive files like “/etc/passwd” and “/etc/shadow.”
The vulnerability was responsibly reported to TP-Link after being discovered on October 3, 2024. Key events in the disclosure timeline include:
October 10, 2024: TP-Link was contacted and investigated the vulnerability. On November 8, 2024, they confirmed the issue and released a beta firmware fix.
November 23, 2024: MITRE has reserved CVE-ID 2024-53375 for this vulnerability. To address it, TP-Link should ensure proper input sanitization for the ownerId variable, using Lua’s tonumber function to avoid text injection.
This discovery highlights the need for ongoing security audits and responsible disclosure in network device firmware.
TP-Link router users should update their firmware promptly when patches are released to protect against this vulnerability.