RCE in Draytek Vigor2960

CVE-2021-43118

A Remote Command Injection vulnerability exists in DrayTek Vigor 2960 1.5.1.3, DrayTek Vigor 3900 1.5.1.3, and DrayTek Vigor 300B 1.5.1.3 via a crafted HTTP message containing malformed QUERY STRING in mainfunction.cgi, which could let a remote malicious user execute arbitrary code.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.348 (98.4th percentile), scored .

Moderate probability of exploitation in the next 30 days — watch for active exploitation reports. 98th percentile — 98.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-43118: held from 0.348 to 0.348.

EPSS over last 30 days · oldest: 0.348 · newest: 0.348 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-43118?
CVE-2021-43118 is a critical-severity vulnerability in Draytek Vigor2960, classified under Command Injection. CVSS score: 9.8/10. Published 2022-03-29.
How severe is CVE-2021-43118?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-43118 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.