Cyber Resilience

CVE-2024-27903

Openvpn ≤ 2.5.10

Published
08 July 2024
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.089 95th percentile
Risk Priority 80 floored blend · peak EPSS

Summary

CVE-2024-27903 is a critical-severity Unverified Ownership (CWE-283) vulnerability in Openvpn Openvpn. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to AC-24 (Access Control Decisions) and AC-25 (Reference Monitor) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

OpenVPN versions 2.6.9 and earlier on Windows contain a flaw in plug-in loading that permits plug-ins to be loaded from any directory rather than a restricted path. This affects the OpenVPN interactive service component and is tracked under CWE-283 and CWE-434, with a CVSS 3.1 base score of 9.8 reflecting network-accessible attack vectors without authentication requirements.

An unauthenticated remote attacker can place or reference an arbitrary plug-in binary that the service will load, enabling direct interaction with the privileged OpenVPN process. Successful exploitation grants the attacker full control over confidentiality, integrity, and availability of the affected system.

The referenced OpenVPN security advisories and community wiki entries describe the issue and point to updated builds that enforce directory restrictions for plug-in loading. The associated EPSS score has remained flat at 0.0699 with no material increase since disclosure.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

OpenVPN plug-ins on Windows with OpenVPN 2.6.9 and earlier could be loaded from any directory, which allows an attacker to load an arbitrary plug-in which can be used to interact with the privileged OpenVPN interactive service.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1505 Server Software Component Persistence
Adversaries may abuse legitimate extensible development features of servers to establish persistent access to systems.
T1505.003 Web Shell Persistence
Adversaries may backdoor web servers with web shells to establish persistent access to systems.
T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
T1105 Ingress Tool Transfer Command And Control
Adversaries may transfer tools or other files from an external system into a compromised environment.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-13379Same product: Openvpn Openvpn
CVE-2024-5594Same product: Openvpn Openvpn
CVE-2026-13117Same product: Openvpn Openvpn
CVE-2026-40215Same product: Openvpn Openvpn
CVE-2024-27459Same product: Openvpn Openvpn
CVE-2026-11604Same product: Openvpn Openvpn
CVE-2024-28882Same product: Openvpn Openvpn
CVE-2025-12106Same product: Openvpn Openvpn
CVE-2025-13086Same product: Openvpn Openvpn
CVE-2024-24974Same product: Openvpn Openvpn

Affected Assets

openvpn
openvpn
≤ 2.5.10 · 2.6.0 — 2.6.10

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 4 hardening rules · 4 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V5.1.1

Mitigating Controls (NIST 800-53 r5) AI

Access enforcement directly requires verifying ownership before granting access to resources.

Requiring access decisions to consider all relevant attributes includes ownership verification.

A reference monitor provides the tamperproof mechanism that can enforce ownership checks.

Malicious-code protection at entry points blocks dangerous file types from being accepted and executed.

Associating ownership as a security attribute enables subsequent verification of resource ownership.

Least functionality restricts the file types and automatic processing capabilities the system will accept.

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.AA-05 mostly match
prevents

Enforcing defined access permissions and authorizations directly prevents missing ownership verification for resources.

PR.PS-05 mostly match
prevents

Restricting execution of unauthorized software directly blocks dangerous uploaded files from running.

PR.PS-01 partial match
prevents

Hardened configuration baselines can enforce allowed file types and processing rules.

PR.PS-06 partial match
prevents

Secure development practices include input validation and file-type restrictions that prevent this weakness.

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.

finds

Configuration and acceptance testing verify that file-upload handling enforces allowed types and does not permit dangerous content to be stored or executed.

prevents

Access control policies can require ownership verification before granting access to critical resources.

degrades

Identity management processes can include verification of resource ownership during provisioning and access decisions.

prevents

Access rights reviews can enforce checks that only legitimate owners retain privileges over critical assets.

prevents

Privileged access rights assignment should verify ownership to prevent unauthorized elevation on critical resources.

prevents

Secure-coding guidelines and security testing explicitly address restrictions on allowed file types and upload handling, reducing the risk that dangerous file uploads are accepted without validation.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Windows Server 2016 (1 rule)
  • V-224831 Local volumes must use a format that supports NTFS attributes. prevents CWE-283
Windows Server 2019 (1 rule)
  • V-205663 Windows Server 2019 local volumes must use a format that supports NTFS attributes. prevents CWE-283

References