CVE-2020-15415Known exploitationPublic exploitNetwork attack vector

Unauthenticated command execution via upload filename

Published Jun 30, 2020 · Updated Oct 21, 2025

OS command injection in DrayTek Vigor3900, Vigor2960, and Vigor300B before 1.5.1 allows remote attackers to execute commands. The cvmcfgupload handler in cgi-bin/mainfunction.cgi interprets shell metacharacters embedded in a multipart filename as commands when the part uses text/x-python-script. No authentication or user interaction is required, and successful exploitation grants command execution on the router.

CVSS severity9.8
Critical
EPSS probability84.48%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in DrayTek Vigor3900, Vigor2960, and Vigor300B before 1.5.1 allows remote attackers to execute commands. The cvmcfgupload handler in cgi-bin/mainfunction.cgi interprets shell metacharacters embedded in a multipart filename as commands when the part uses text/x-python-script. No authentication or user interaction is required, and successful exploitation grants command execution on the router.

The record

CVE
CVE-2020-15415
Published
Jun 30, 2020
Updated
Oct 21, 2025
Vendor
DrayTek
Product
Vigor 300B
Classifications
CWE-78, T1059.004, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 30, 2020CVE publishedPublication date reported by the CVE source.
  2. Sep 30, 2024Exploitation reportedCISA Known Exploited Vulnerabilities listing
  3. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

DrayTek · Vigor 300Bversion=0 <1.5.1
DrayTek · Vigor3900 Firmwareversion=0 <1.5.1
DrayTek · Vigor 2960version=0 <1.5.1

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsShadowserver observations through Sep 15, 2026. Gaps indicate unavailable data.
Sep 9, 2026Sep 15, 2026
View daily counts
Reporting dayUnique IPs
Sep 9, 2026Unavailable
Sep 10, 2026Unavailable
Sep 11, 2026Unavailable
Sep 12, 2026Unavailable
Sep 13, 2026Unavailable
Sep 14, 20262
Sep 15, 20261
Latest reporting daySep 15, 2026
Latest daily unique IPs1
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.004Unix Shell
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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