OpenVPN before 2.0.1 does not properly flush the OpenSSL error queue when a packet can not be decrypted by the server, which allows remote a
OpenVPN before 2.0.1 does not properly flush the OpenSSL error queue when a packet can not be decrypted by the server, which allows remote authenticated attackers to cause a denial of service (client disconnection) via a large number of packets that can not be decrypted.
- Published
- Aug 24, 2005
- Updated
- Jun 16, 2026
- EPSS
- 2.7% · 86th percentile
- CWE
- —
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 20 / 40 · 5.0 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 1 / 30 · 2.7%
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| openvpn | openvpn | cpe:2.3:a:openvpn:openvpn |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- openvpn openvpn2.0
- openvpn openvpn2.0_beta1
- openvpn openvpn2.0_beta10
- openvpn openvpn2.0_beta11
- openvpn openvpn2.0_beta12
- openvpn openvpn2.0_beta13
- openvpn openvpn2.0_beta15
- openvpn openvpn2.0_beta16
- openvpn openvpn2.0_beta17
- openvpn openvpn2.0_beta18
- openvpn openvpn2.0_beta19
- openvpn openvpn2.0_beta2
- openvpn openvpn2.0_beta20
- openvpn openvpn2.0_beta28
- openvpn openvpn2.0_beta3
- openvpn openvpn2.0_beta4
- openvpn openvpn2.0_beta5
- openvpn openvpn2.0_beta6
- openvpn openvpn2.0_beta7
- openvpn openvpn2.0_beta8
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | openvpn | before 2.0.2-1 | 2.0.2-1 |
| Debian:3.1 | openvpn | before 2.0-1sarge1 | 2.0-1sarge1 |
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 |
|---|---|---|
| debian:openvpn | 2.0.2-1 · Debian:12 | 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
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- P · the service can be disrupted
- Attack complexity
- Low
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- P
Weakness class (CWE)
—
CVSS vector
AV:N/AC:L/Au:N/C:N/I:N/A:P
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.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; 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 helpChange log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- openvpn.net/changelog.html
- secunia.com/advisories/16463
- secunia.com/advisories/17103
- www.debian.org/security/2005/dsa-851
- www.mandriva.com/security/advisories?name=MDKSA-2005:145
- www.securityfocus.com/bid/14607
Vendor advisories and official records. Exploit/PoC links are deliberately left out.