Arbitrary File Read Vulnerability in Yonyou U8 CRM Products
CVE-2023-54403

8.7HIGH

Key Information:

Vendor

Yonyou

Status
U8 Crm
Vendor
CVE Published:
30 September 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2023-54403?

The Yonyou U8 CRM software versions before V16.5 and V18 contain a vulnerability in the /ajax/getemaildata.php file, which allows unauthenticated users to bypass authentication by manipulating the DontCheckLogin parameter. This vulnerability permits the reading of arbitrary files through an unvalidated filePath parameter, potentially exposing sensitive information outside the intended directory. Attackers can exploit this flaw to access critical configuration files that may contain database or service credentials, posing significant risks to data security. Evidence of exploitation was first detected by the Shadowserver Foundation on October 14, 2023.

Affected Version(s)

U8 CRM 16.1

U8 CRM 16.0

U8 CRM 15.1

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-2023-54403 - Proof of Concept

References

https://security.yonyou.com/#/noticeInfo?id=624
vendor-advisorypatch
https://github.com/projectdiscovery/nuclei-templates/blob...
technical-description
https://github.com/PeiQi0/PeiQi-WIKI-Book/blob/main/docs/...
exploit

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
None
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
.