OpenVPN 2.5.1 and earlier versions allows a remote attackers to bypass authentication and access control channel data on servers configured
OpenVPN 2.5.1 and earlier versions allows a remote attackers to bypass authentication and access control channel data on servers configured with deferred authentication, which can be used to potentially trigger further information leaks.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for help- Published
- Apr 26, 2021
- Updated
- Jun 16, 2026
- EPSS
- 4.9% · 92th percentile
- CWE
- CWE-305
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 30 / 40 · 7.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 4.9%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| openvpn | openvpn | cpe:2.3:a:openvpn:openvpn |
| fedoraproject | fedora | cpe:2.3:o:fedoraproject:fedora |
| canonical | ubuntu linux | cpe:2.3:o:canonical:ubuntu_linux |
| debian | debian linux | cpe:2.3:o:debian:debian_linux |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- canonical ubuntu linux18.04
- canonical ubuntu linux20.04
- canonical ubuntu linux20.10
- canonical ubuntu linux21.04
- debian debian linux9.0
- fedoraproject fedora32
- fedoraproject fedora33
- fedoraproject fedora34
- openvpn openvpn2.5.0 and later · before 2.5.2
- openvpn openvpnbefore 2.4.11
Versions reported by the vendor
Affected version ranges reported by the assigning authority (OpenVPN). Independent of NVD's CPE analysis and usually ahead of it.
n/a OpenVPN
- 2.5.1 and earlier versionsaffected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Alpine:v3.10 | openvpn | from 2.5.0 · before 2.4.11-r0 | 2.4.11-r0 |
| Alpine:v3.13 | openvpn | from 2.5.0 · before 2.5.2-r0 | 2.5.2-r0 |
| Debian:12 | openvpn | before 2.5.1-2 | 2.5.1-2 |
| Debian:9 | openvpn | before 2.4.0-6+deb9u4 | 2.4.0-6+deb9u4 |
| openSUSE:Leap 15.2 | openvpn | before 2.4.3-lp152.6.3.1 | 2.4.3-lp152.6.3.1 |
| openSUSE:Tumbleweed | openvpn | before 2.5.3-1.2 | 2.5.3-1.2 |
| SUSE:Linux Enterprise Module for Basesystem 15 SP2 | openvpn | before 2.4.3-5.7.1 | 2.4.3-5.7.1 |
| SUSE:Linux Enterprise Server 11-SECURITY | openvpn-openssl1 | before 2.3.2-0.10.9.1 | 2.3.2-0.10.9.1 |
| SUSE:Linux Enterprise Server 12 SP5 | openvpn | before 2.3.8-16.26.1 | 2.3.8-16.26.1 |
Same product
openvpn: all recordsOther highest-scoring records for the same primary product.
- CVE-2024-27903OpenVPN plug-ins on Windows with OpenVPN 2.6.9 and earlier could be loaded from any directory, which allows an attacker to load an arbitrary42Plan
- CVE-2023-46850Use after free in OpenVPN version 2.6.0 to 2.6.6 may lead to undefined behavoir, leaking memory buffers or remote execution when sending net40Plan
- CVE-2022-0547OpenVPN 2.1 until v2.4.12 and v2.5.6 may enable authentication bypass in external authentication plug-ins when more than one of them makes u40Plan
- CVE-2017-12166OpenVPN versions before 2.3.3 and 2.4.x before 2.4.4 are vulnerable to a buffer overflow vulnerability when key-method 1 is used, possibly r40Plan
- CVE-2025-10680OpenVPN 2.7_alpha1 through 2.7_beta1 on POSIX based platforms allows a remote authenticated server to inject shell commands via DNS variable37Monitor
- CVE-2018-7544A cross-protocol scripting issue was discovered in the management interface in OpenVPN through 2.4.5.37Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| alpine:openvpn | 2.4.11-r0 · Alpine:v3.10 | Package registry (OSV) |
| debian:openvpn | 2.5.1-2 · Debian:12 | Package registry (OSV) |
| opensuse:openvpn | 2.4.3-lp152.6.3.1 · openSUSE:Leap 15.2 | Package registry (OSV) |
| suse:openvpn | 2.3.8-16.26.1 · SUSE:Linux Enterprise Server 12 SP5 | Package registry (OSV) |
| suse:openvpn-openssl1 | 2.3.2-0.10.9.1 · SUSE:Linux Enterprise Server 11-SECURITY | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- none
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-305 · Authentication Bypass by Primary WeaknessCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- community.openvpn.net/openvpn/wiki/CVE-2020-15078
- community.openvpn.net/openvpn/wiki/SecurityAnnouncements
- lists.debian.org/debian-lts-announce/2022/05/msg00002.html
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GJUXEYHUPREEBPX23VPEKMFXUPVO3PMU/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JGEGLC4YGBDN5CGHTNWN2GH6DJJA36T2/
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PLDB3OBQ3AODYYRN7NRCABV6I4AUFAT6/
- security.gentoo.org/glsa/202105-25
- usn.ubuntu.com/usn/usn-4933-1
Vendor advisories and official records. Exploit/PoC links are deliberately left out.