CVE-2025-55824Public exploitNetwork attack vector

Command execution via crafted upgrade package

Published Sep 2, 2025 · Updated Sep 3, 2025

Arbitrary file write in ModStartCMS 9.5.0 allows remote authenticated users to execute commands by submitting crafted upgrade files. UpgradeController passes attacker-supplied package and diff-file paths to UpgradeUtil::upgradePackage, which writes archive content to a path named in the diff. A valid backend session and uploaded ZIP and text files are required; successful exploitation writes a PHP backdoor under the public web root, enabling command execution and sensitive-data access.

CVSS severity6.5
Medium
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary file write in ModStartCMS 9.5.0 allows remote authenticated users to execute commands by submitting crafted upgrade files. UpgradeController passes attacker-supplied package and diff-file paths to UpgradeUtil::upgradePackage, which writes archive content to a path named in the diff. A valid backend session and uploaded ZIP and text files are required; successful exploitation writes a PHP backdoor under the public web root, enabling command execution and sensitive-data access.

The record

CVE
CVE-2025-55824
Published
Sep 2, 2025
Updated
Sep 3, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-77, T1505.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 3, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')
T1505.003Web Shell

Public exploit references

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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