CVE-2023-27397Network attack vector

Unauthenticated code execution via unrestricted file upload

Published May 23, 2023 · Updated Jan 31, 2025

Unrestricted file upload in MicroEngine Mailform 1.1.0 through 1.1.8 allows remote attackers to execute files saved on the web server. The file-upload function insufficiently validates file types before the server-save option writes attacker-controlled content to server storage. Exploitation requires both file uploads and config.ini save_file=1; successful uploads execute with the web server's privileges.

CVSS severity9.8
Critical
EPSS probability0.92%
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 MicroEngine Mailform 1.1.0 through 1.1.8 allows remote attackers to execute files saved on the web server. The file-upload function insufficiently validates file types before the server-save option writes attacker-controlled content to server storage. Exploitation requires both file uploads and config.ini save_file=1; successful uploads execute with the web server's privileges.

The record

CVE
CVE-2023-27397
Published
May 23, 2023
Updated
Jan 31, 2025
Vendor
MicroEngine Inc.
Product
MicroEngine Mailform
Classifications
CWE-434, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 23, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 31, 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=version 1.1.0 to 1.1.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

MicroEngine Inc. · MicroEngine Mailformversion=version 1.1.0 to 1.1.8

Published CVSS scores

3.7JVNCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
9.8CISA ADP VulnrichmentCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
4.3JVNAV:N/AC:M/Au:N/C:N/I:P/A:N

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
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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