Findings

Vulnerability · CVE-2023-54403

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Published Sep 30, 2026 · corrected/updated Sep 30, 2026 · Yonyou U8 CRM · evidence confidence very high

Yonyou U8 CRM before V16.5 and V18 contains an arbitrary file read vulnerability in /ajax/getemaildata.php that allows unauthenticated attackers to bypass authentication using the DontCheckLogin=1 parameter and read arbitrary files via an unvalidated filePath parameter. Attackers can exploit this flaw to read sensitive files outside the web application directory, including configuration files containing database or service credentials. Exploitation evidence was first observed by the Shadowserver Foundation on 2023-10-14.

Grounded briefings

Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.

Executive

CVE-2023-54403 is a unknown public vulnerability record for Yonyou U8 CRM. CISA lists it as known exploited. Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.

System administrator

Identify whether Yonyou U8 CRM is in your estate, then compare installed versions with the affected ranges. Affected packages or ranges on record: Yonyou U8 CRM. Published remediation guidance: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.

Security analyst

Signals on file: EPSS 0.5%. CISA lists it as known exploited. Sources contributing to this record: epss, vulncheck_kev. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.

Exploitation and remediation

  • Exploitation evidence

    Confirmed in CISA KEV since Sep 30, 2026. Listed in CISA KEV and VulnCheck KEV.

  • Patch and remediation

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 30, 2026 · VulnCheck KEV

    Detected

    Yonyou U8 CRM before V16.5 and V18 contains an arbitrary file read vulnerability in /ajax/getemaildata.php that allows unauthenticated attackers to bypass authentication using the DontCheckLogin=1 parameter and read arbitrary files via an unvalidated filePath parameter. Attackers can exploit this flaw to read sensitive files outside the web application directory, including configuration files cont

  2. Sep 30, 2026 · CISA KEV

    Known exploited

    Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Affected

  • vendor Yonyou U8 CRMversion unspecified

Sources

  • FIRST EPSSExploitation probabilityCVE-2023-54403

    30-day exploitation probability 0.5%

    first.org
  • VulnCheck KEVConfirmed exploitationCVE-2023-54403

    Yonyou U8 CRM before V16.5 and V18 contains an arbitrary file read vulnerability in /ajax/getemaildata.php that allows unauthenticated attackers to bypass authentication using the DontCheckLogin=1 parameter and read arbitrary files via an unvalidated filePath parameter. Attackers

    vulncheck.com

References