CVE-2017-6884

CVE-2017-6884 is a high-severity (CVSS 8.8) vulnerability in Zyxel EMG2926 Routers. CISA added it to the Known Exploited Vulnerabilities catalog on September 18, 2023, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by October 9, 2023. CISA also lists it as known to be used in ransomware campaigns, so it should be prioritised accordingly. Zyxel has 13 vulnerabilities in the KEV catalog, 2 of them linked to ransomware.

A command injection vulnerability was discovered on the Zyxel EMG2926 home router with firmware V1.00(AAQT.4)b8. The vulnerability is located in the diagnostic tools, specifically the nslookup function. A malicious user may exploit numerous vectors to execute arbitrary commands on the router, such as the ping_ip parameter to the expert/maintenance/diagnostic/nslookup URI.

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

• https://www.exploit-db.com/exploits/41782/
• https://www.exploit-db.com/exploits/41782/
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-6884