Cyber Resilience

CVE-2025-34238

Path Traversal in Advantech Webaccess\/Vpn ≤ 1.1.5

Public PoCPath Traversal
Published
06 November 2025
Modified
04 December 2025
Patch / advisory
CVSS Score v4 6.9
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0037 30th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2025-34238 is a medium-severity Path Traversal (CWE-22) vulnerability in Advantech Webaccess\/Vpn. Its CVSS base score is 6.9 (Medium).

Operationally, ranked at the 30th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to AC-6 (Least Privilege) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Advantech WebAccess/VPN versions prior to 1.1.5 contain an absolute path traversal via AjaxStandaloneVpnClientsController.ajaxDownloadRoadWarriorConfigFileAction() that allows an authenticated network administrator to cause the application to read and return the contents of arbitrary files the web user (www-data) can access.

CWE(s)

Related Threats

CVEs Like This One

CVE-2025-58423Same vendor: Advantech
CVE-2025-67653Same vendor: Advantech
CVE-2025-62630Same vendor: Advantech
CVE-2017-16720Same vendor: Advantech
CVE-2025-46704Same vendor: Advantech
CVE-2025-14850Same vendor: Advantech
CVE-2025-59171Same vendor: Advantech
CVE-2023-37218Shared CWE-22
CVE-2026-41655Shared CWE-22
CVE-2025-7712Shared CWE-22

Affected Assets

advantech
webaccess\/vpn
≤ 1.1.5

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SI-10 Information Input Validation
  • AC-6 Least Privilege
  • AC-3 Access Enforcement
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.3.2

Mitigating Controls (NIST 800-53 r5) AI

prevent

Validates file-path parameters supplied to ajaxDownloadRoadWarriorConfigFileAction() to block absolute traversal sequences before any file read occurs.

prevent

Restricts the www-data process to only the minimal set of files required for VPN configuration, preventing read access to arbitrary system files even if traversal succeeds.

prevent

Enforces fine-grained access-control checks on the specific resource or object referenced by the download action rather than relying solely on the caller's administrator role.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-02 partial match
prevents

Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.

PR.AA-05 none match
prevents

PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing in development catches path traversal via static/dynamic analysis.

prevents

Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.

prevents

Application security requirements include rules for safe file handling and canonicalization.

prevents

Secure architecture principles require least-privilege file access and directory isolation.

prevents

Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.

mitigates

Information access restriction limits which files an application may read or write.

References