OpenVPN up to 2.0.3 Exception accept denial of service

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.1$0-$5k0.00

Summaryinfo

A vulnerability was found in OpenVPN up to 2.0.3 and classified as problematic. This impacts the function Accept of the component Exception Handler. The manipulation results in denial of service. This vulnerability is reported as CVE-2005-3409. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in OpenVPN up to 2.0.3 (Network Encryption Software). It has been classified as problematic. Affected is the function accept of the component Exception Handler. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. CVE summarizes:

OpenVPN 2.x before 2.0.4, when running in TCP mode, allows remote attackers to cause a denial of service (segmentation fault) by forcing the accept function call to return an error status, which leads to a null dereference in an exception handler.

The bug was discovered 10/31/2005. The weakness was disclosed 11/01/2005 (Website). The advisory is shared for download at secunia.com. This vulnerability is traded as CVE-2005-3409 since 11/01/2005. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available.

The vulnerability was handled as a non-public zero-day exploit for at least 1 days. During that time the estimated underground price was around $0-$5k. The vulnerability scanner Nessus provides a plugin with the ID 21416 (FreeBSD : openvpn -- potential denial-of-service on servers in TCP mode (3de49331-0dec-422c-93e5-e4719e9869c5)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family FreeBSD Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 38487 (OpenVPN Server Remote Denial of Service Vulnerability).

Upgrading to version 2.x eliminates this vulnerability. A possible mitigation has been published before and not just after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (21416), SecurityFocus (BID 15270†), OSVDB (20416†), Secunia (SA17376†) and Vulnerability Center (SBV-10909†). The entries VDB-26743, VDB-26146, VDB-26145 and VDB-26144 are pretty similar. Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Denial of service
CWE: CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 21416
Nessus Name: FreeBSD : openvpn -- potential denial-of-service on servers in TCP mode (3de49331-0dec-422c-93e5-e4719e9869c5)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍
Nessus Port: 🔍

OpenVAS ID: 55815
OpenVAS Name: Debian Security Advisory DSA 885-1 (openvpn)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: OpenVPN 2.x

Timelineinfo

10/31/2005 🔍
11/01/2005 +1 days 🔍
11/01/2005 +0 days 🔍
11/01/2005 +0 days 🔍
11/01/2005 +0 days 🔍
11/01/2005 +0 days 🔍
11/01/2005 +0 days 🔍
11/01/2005 +0 days 🔍
11/01/2005 +0 days 🔍
04/03/2006 +152 days 🔍
05/13/2006 +40 days 🔍
03/11/2015 +3224 days 🔍
06/29/2025 +3763 days 🔍

Sourcesinfo

Advisory: secunia.com⛔
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2005-3409 (🔍)
GCVE (CVE): GCVE-0-2005-3409
GCVE (VulDB): GCVE-100-26772
SecurityFocus: 15270 - OpenVPN Server Remote Denial Of Service Vulnerability
Secunia: 17376 - OpenVPN Format String and Denial of Service Vulnerabilities, Moderately Critical
OSVDB: 20416 - OpenVPN TCP Mode accept() Function Failure NULL Dereference DoS
Vulnerability Center: 10909 - OpenVPN DoS via the Accept Function, Medium

See also: 🔍

Entryinfo

Created: 03/11/2015 23:39
Updated: 06/29/2025 02:35
Changes: 03/11/2015 23:39 (81), 06/16/2019 09:17 (2), 06/29/2025 02:35 (20)
Complete: 🔍
Cache ID: 216::103

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