Unauthenticated command execution via unsafe servlet deserialization
Published Sep 15, 2026 · Updated Sep 15, 2026
Java deserialization in Yonyou U8 Cloud 1.0 through 3.6sp allows remote attackers to execute OS commands through an unauthenticated POST request. FileManageServlet.doAction passes the raw request stream to ObjectInputStream.readObject without restricting deserialized classes, enabling a bundled gadget chain. No account or user interaction is required; successful exploitation runs commands with the application server's privileges and can compromise its host.
Summary
What happened
Java deserialization in Yonyou U8 Cloud 1.0 through 3.6sp allows remote attackers to execute OS commands through an unauthenticated POST request. FileManageServlet.doAction passes the raw request stream to ObjectInputStream.readObject without restricting deserialized classes, enabling a bundled gadget chain. No account or user interaction is required; successful exploitation runs commands with the application server's privileges and can compromise its host.
The record
- CVE
- CVE-2023-54398
- Published
- Sep 15, 2026
- Updated
- Sep 15, 2026
- Vendor
- Yonyou Network Technology Co., Ltd.
- Product
- U8 Cloud
- Classifications
- T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 13, 2025Exploitation reportedShadowserver FileManageServlet exploitation observation
- Sep 15, 2026CVE publishedPublication date reported by the CVE source.
- Sep 15, 2026Record 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.
- Affected versionversion=1.0
- Affected versionversion=2.0
- Affected versionversion=2.1
- Affected versionversion=2.3
- Affected versionversion=2.5
- Affected versionversion=2.6
- Affected versionversion=2.65
- Affected versionversion=2.7
- Affected versionversion=3.0
- Affected versionversion=3.1
- Affected versionversion=3.2
- Affected versionversion=3.5
- Affected versionversion=3.6
- Affected versionversion=3.6sp
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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.
Weakness, pattern, technique
Public exploit references
- FileManageServlet deserialization proof of conceptfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
Technologies
Your stack
See the directory against your own environment.
Your stack
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