IRONSMITHINTEL
CRITICALCVSS9.8
|
Actively Exploited
|CISA KEV|CVE-2020-15415|Auth: none — unauthenticated|Reboot: required|Manual only

DrayTek Multiple Vigor Routers OS Command Injection Vulnerability

DrayTek Vigor3900, Vigor2960, and Vigor300B devices contain an OS command injection vulnerability in cgi-bin/mainfunction.cgi/cvmcfgupload that allows for remote code execution via shell metacharacters in a filename when the text/x-python-script content type is used.

Published Jun 30, 2020 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve full data confidentiality loss, arbitrary modification of data, complete denial of service or system unavailability. Federal agencies are required to remediate by 2024-10-21 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a OS Command Injection (CWE-78) vulnerability in DrayTek Multiple Vigor Routers. On DrayTek Vigor3900, Vigor2960, and Vigor300B devices before 1.5.1, cgi-bin/mainfunction.cgi/cvmcfgupload allows remote command execution via shell metacharacters in a filename when the text/x-python-script content type is used, a different issue than CVE-2020-14472. Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.

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Phishing link

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Malicious file

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Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

IT Security
Running vigor3900 firmware: v < 1.5.1; vigor2960 firmware: v < 1.5.1; vigor300b firmware: v < 1.5.1
Real-world incidentsWhat we've seen

Active exploitation documented in the wild. Threat-research write-up: https://github.com/CLP-team/Vigor-Commond-Injection

How to patch

Manual remediation steps

Apply the Vendor Patch

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.

CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

References

    1
    Vendor advisory: https://www.draytek.com/about/security-advisory/vigor3900-/-vigor2960-/-vigor300b-remote-code-injection/execution-vulnerability-(cve-2020-14472)
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2020-15415
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-15415
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