CVE-2021-42911

CRITICAL

DrayTek Vigor 2960, 3900, and 300B <= 1.5.1.3 - Remote Code Execution via Format String in mainfunction.cgi

Title source: llm
STIX 2.1

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.

References (1)

Core 1
Core References
Exploit, Third Party Advisory x_refsource_misc
https://gist.github.com/Cossack9989/e9c1c2d2e69b773ca4251acdd77f2835

Scores

CVSS v3 9.8
EPSS 0.0330
EPSS Percentile 86.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

CWE
CWE-134
Status published
Products (3)
draytek/vigor2960_firmware < 1.5.1.3
draytek/vigor300b_firmware < 1.5.1.3
draytek/vigor3900_firmware < 1.5.1.3
Published Mar 29, 2022
Tracked Since Feb 18, 2026