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Vulnerability record · CVE-2021-43118 · published 29 March 2022

CVE-2021-43118: Draytek vigor2960 firmware command injection vulnerability

Draytek · Vigor2960 Firmware

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.

9.8 CVSS 3.1 Critical EPSS 35% · top 1.6% CWE-77 · Command injection
9.8CVSS 3.1 base score, v2 7.5
35%EPSS exploitation probability, 30 days
NoNot in CISA KEV
3Affected product versions listed by NVD
2References, 2 tagged exploit
17 Jun 2026Last modified by NVD

Description

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.

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

Affected products

3 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://gist.github.com/Cossack9989/6034c077f46e4f06d0992e9f2fae7f26 ExploitThird Party Advisory
https://gist.github.com/Cossack9989/6034c077f46e4f06d0992e9f2fae7f26 ExploitThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2020-15415DrayTek Vigor routers OS command injection in cvmcfguploadDrayTek Vigor3900, Vigor2960 and Vigor300B devices before firmware 1.5.1 allow OS command injection through shell metacharacters in a filename upload…KEVEPSS 84%analysed9.8CVE-2020-8515DrayTek Vigor routers unauthenticated OS command injection in web managementDrayTek Vigor2960, Vigor3900 and Vigor300B firmware pass shell metacharacters to cgi-bin/mainfunction.cgi, allowing OS command injection. Because the…KEVEPSS 100%analysed6.9CVE-2024-12987DrayTek Vigor router web interface OS command injectionDrayTek Vigor2960 and Vigor300B firmware 1.5.1.4 contain an OS command injection flaw in the /cgi-bin/mainfunction.cgi/apmcfgupload endpoint of the w…KEVEPSS 98%analysed9.8CVE-2024-51252Draytek vigor3900 firmware os command injection vulnerabilityIn Draytek Vigor3900 1.5.1.3, attackers can inject malicious commands into mainfunction.cgi and execute arbitrary commands by calling the restore fun…EPSS 0.82%9.8CVE-2024-51255Draytek vigor3900 firmware command injection vulnerabilityDrayTek Vigor3900 1.5.1.3 allows attackers to inject malicious commands into mainfunction.cgi and execute arbitrary commands by calling the ruequest_…EPSS 0.39%9.8CVE-2024-51260Draytek vigor3900 firmware command injection vulnerabilityDrayTek Vigor3900 1.5.1.3 allows attackers to inject malicious commands into mainfunction.cgi and execute arbitrary commands by calling the acme_proc…EPSS 0.62%9.8CVE-2024-51259Draytek vigor3900 firmware command injection vulnerabilityDrayTek Vigor3900 1.5.1.3 allows attackers to inject malicious commands into mainfunction.cgi and execute arbitrary commands by calling the setup_cac…EPSS 0.35%9.8CVE-2024-51298Draytek vigor3900 firmware code injection vulnerabilityIn Draytek Vigor3900 1.5.1.3, attackers can inject malicious commands into mainfunction.cgi and execute arbitrary commands by calling the doGRETunnel…EPSS 0.62%

Source: NIST National Vulnerability Database (record CVE-2021-43118), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.