Java Deserialization Vulnerability in Yonyou U8 Cloud
CVE-2023-54398

9.3CRITICAL

Key Information:

Vendor

Yonyou

Status
U8 Cloud
Vendor
CVE Published:
15 September 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2023-54398?

Yonyou U8 Cloud features an unauthenticated vulnerability within the nc.impl.pub.filesystem.FileManageServlet component, allowing remote attackers to execute arbitrary operating system commands. This security flaw is rooted in the doAction method, where raw HTTP request data is processed directly through ObjectInputStream.readObject() without any input validation. By crafting a malicious serialized payload, an attacker can exploit this vulnerability to achieve remote code execution, posing significant risks to system integrity.

Affected Version(s)

U8 Cloud 1.0

U8 Cloud 2.0

U8 Cloud 2.1

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2023-54398 - Proof of Concept

References

https://security.yonyou.com/#/noticeInfo?id=400
vendor-advisorypatch
https://cn-sec.com/archives/2182384.html
technical-descriptionexploit
https://blog.csdn.net/qq_41904294/article/details/134277353
technical-descriptionexploit

CVSS V4

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

The Shadowserver Foundation
.