CVE-2025-3110: CWE-444 Inconsistent interpretation of HTTP requests ('HTTP Request/Response smuggling') in OpenVPN Access Server
OpenVPN Access Server 2.7.2 through 3.1.0 accepts bare line-feed sequences inside HTTP header values, allowing remote attackers to perform HTTP request smuggling when deployed behind a reverse proxy
AI Analysis
Technical Summary
CVE-2025-3110 is an HTTP request smuggling vulnerability in OpenVPN Access Server versions 2.7.2 through 3.1.0. The issue arises because the server accepts bare line-feed characters within HTTP header values, which can be exploited by remote attackers to manipulate HTTP requests when the server is behind a reverse proxy. This inconsistent interpretation of HTTP requests can lead to request smuggling attacks classified under CWE-444.
Potential Impact
The vulnerability allows remote attackers to perform HTTP request smuggling, potentially enabling them to bypass security controls or interfere with the processing of HTTP requests by the reverse proxy and the OpenVPN Access Server. The CVSS score of 6.9 reflects a medium impact with network attack vector, low attack complexity, no privileges or user interaction required, and limited impact on integrity and availability.
Mitigation Recommendations
No official patch or remediation is currently available for this vulnerability. Users should monitor the OpenVPN vendor advisory for updates and apply any official fixes once released. In the meantime, consider deploying additional protections at the reverse proxy level to detect or block malformed HTTP requests containing bare line-feed sequences.
CVE-2025-3110: CWE-444 Inconsistent interpretation of HTTP requests ('HTTP Request/Response smuggling') in OpenVPN Access Server
Description
OpenVPN Access Server 2.7.2 through 3.1.0 accepts bare line-feed sequences inside HTTP header values, allowing remote attackers to perform HTTP request smuggling when deployed behind a reverse proxy
CVSS v4.0
Score 6.9medium
Affected software
pkg:github/openvpn/access-serverRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2025-3110 is an HTTP request smuggling vulnerability in OpenVPN Access Server versions 2.7.2 through 3.1.0. The issue arises because the server accepts bare line-feed characters within HTTP header values, which can be exploited by remote attackers to manipulate HTTP requests when the server is behind a reverse proxy. This inconsistent interpretation of HTTP requests can lead to request smuggling attacks classified under CWE-444.
Potential Impact
The vulnerability allows remote attackers to perform HTTP request smuggling, potentially enabling them to bypass security controls or interfere with the processing of HTTP requests by the reverse proxy and the OpenVPN Access Server. The CVSS score of 6.9 reflects a medium impact with network attack vector, low attack complexity, no privileges or user interaction required, and limited impact on integrity and availability.
Mitigation Recommendations
No official patch or remediation is currently available for this vulnerability. Users should monitor the OpenVPN vendor advisory for updates and apply any official fixes once released. In the meantime, consider deploying additional protections at the reverse proxy level to detect or block malformed HTTP requests containing bare line-feed sequences.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- OpenVPN
- Date Reserved
- 2025-04-02T07:56:08.672Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4e7ad4c9d9e3dbe36a7d4e
Added to database: 07/08/2026, 16:29:08 UTC
Last enriched: 07/08/2026, 16:44:43 UTC
Last updated: 07/09/2026, 03:26:59 UTC
Views: 13
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