Exploited vulnerability · CISA KEV

Is CVE-2017-6884 exploited? Yes: in CISA KEV since 18 Sep 2023

Gociux · Zyxel EMG2926 Routers · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2017-6884, Zyxel EMG2926 Routers Command Injection Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 18 Sep 2023, 2356 days after it was published. It is known to be used in ransomware campaigns. It affects Zyxel EMG2926 Routers, an internet-facing product of the kind attackers use for initial access. If you run it, CISA's required action is: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

What it is

Zyxel EMG2926 routers contain a command injection vulnerability located in the diagnostic tools, specifically the nslookup function. A malicious user may exploit numerous vectors to execute malicious commands on the router, such as the ping_ip parameter to the expert/maintenance/diagnostic/nslookup URI.

What to do

1. Check whether you run it. Look for EMG2926 Routers in your asset inventory, including appliances and cloud images. Stack check lists every exploited Zyxel CVE at once.
2. Apply the fix. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 6 Apr 2017.
4. Get told next time. Email alerts when CISA adds a CVE for Zyxel.

References

• www.zyxel.com/global/en/support/security-advisories/zyxel-security-adviso
• nvd.nist.gov/vuln/detail/CVE-2017-6884

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in September 2023 · Zyxel scorecard · act-now radar.