CVE-2021-42911
9.8
CRITICAL · CVSS 3.1 · EPSS 3.5% (pctl 89)
In your normal cycle
Critical by CVSS (9.8), but no sign of active exploitation.
Description
A Format String 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 in the mainfunction.cgi file via a crafted HTTP message containing malformed QUERY STRING, which could let a remote malicious user execute arbitrary code.
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 3.52% — more likely to be exploited than 89% of all CVEs |
| Weakness | CWE-134 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2022-03-29 |
| Last modified | 2026-06-17 |
Affected (6)
| Vendor | Product |
|---|---|
| draytek | vigor2960 |
| draytek | vigor2960 firmware |
| draytek | vigor300b |
| draytek | vigor300b firmware |
| draytek | vigor3900 |
| draytek | vigor3900 firmware |
References
→ the Explorer · watch your stack · NVD