CVE-2021-20659

Code execution via unrestricted PHP file upload

Published Feb 24, 2021 · Updated Aug 3, 2024

Unrestricted file upload in CONTEC SolarView Compact SV-CPT-MC310 before 6.5 allows remote authenticated users to execute PHP code. CONTEC and JVN do not identify the affected upload endpoint or disclose how file-type validation is bypassed. Product credentials and adjacent-network access are required; successful exploitation permits arbitrary code execution on the monitoring appliance.

CVSS severity5.5
Medium
EPSS probability2.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in CONTEC SolarView Compact SV-CPT-MC310 before 6.5 allows remote authenticated users to execute PHP code. CONTEC and JVN do not identify the affected upload endpoint or disclose how file-type validation is bypassed. Product credentials and adjacent-network access are required; successful exploitation permits arbitrary code execution on the monitoring appliance.

The record

CVE
CVE-2021-20659
Published
Feb 24, 2021
Updated
Aug 3, 2024
Vendor
CONTEC Co., Ltd.
Product
SolarView Compact
Classifications
CWE-434, T1505.003, T1190
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 24, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record 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=SV-CPT-MC310 prior to Ver.6.5

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

CONTEC Co., Ltd. · SolarView Compactversion=SV-CPT-MC310 prior to Ver.6.5

Published CVSS scores

6.5NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
5.5JVNCVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
8.8NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.2JVNAV:A/AC:L/Au:S/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 IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1505.003Server Software Component: Web Shell
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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

Technologies

Your stack

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Your stack

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