CVE-2005-2531
First published: Wed Aug 24 2005(Updated: )
OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not properly flush the OpenSSL error queue when a client fails certificate authentication to the server and causes the error to be processed by the wrong client, which allows remote attackers to cause a denial of service (client disconnection) via a large number of failed authentication attempts.
Credit: cve@mitre.org
| Affected Software | Affected Version | How to fix |
|---|---|---|
| OpenVPN Monitor | =2.0 | |
| OpenVPN Monitor | =2.0.1_rc1 | |
| OpenVPN Monitor | =2.0.1_rc2 | |
| OpenVPN Monitor | =2.0.1_rc3 | |
| OpenVPN Monitor | =2.0.1_rc4 | |
| OpenVPN Monitor | =2.0.1_rc5 | |
| OpenVPN Monitor | =2.0.1_rc6 | |
| OpenVPN Monitor | =2.0.1_rc7 | |
| OpenVPN Monitor | =2.0_beta1 | |
| OpenVPN Monitor | =2.0_beta2 | |
| OpenVPN Monitor | =2.0_beta3 | |
| OpenVPN Monitor | =2.0_beta4 | |
| OpenVPN Monitor | =2.0_beta5 | |
| OpenVPN Monitor | =2.0_beta6 | |
| OpenVPN Monitor | =2.0_beta7 | |
| OpenVPN Monitor | =2.0_beta8 | |
| OpenVPN Monitor | =2.0_beta9 | |
| OpenVPN Monitor | =2.0_beta10 | |
| OpenVPN Monitor | =2.0_beta11 | |
| OpenVPN Monitor | =2.0_beta12 | |
| OpenVPN Monitor | =2.0_beta13 | |
| OpenVPN Monitor | =2.0_beta15 | |
| OpenVPN Monitor | =2.0_beta16 | |
| OpenVPN Monitor | =2.0_beta17 | |
| OpenVPN Monitor | =2.0_beta18 | |
| OpenVPN Monitor | =2.0_beta19 | |
| OpenVPN Monitor | =2.0_beta20 | |
| OpenVPN Monitor | =2.0_beta28 | |
| OpenVPN Monitor | =2.0_rc1 | |
| OpenVPN Monitor | =2.0_rc2 | |
| OpenVPN Monitor | =2.0_rc3 | |
| OpenVPN Monitor | =2.0_rc4 | |
| OpenVPN Monitor | =2.0_rc5 | |
| OpenVPN Monitor | =2.0_rc6 | |
| OpenVPN Monitor | =2.0_rc7 | |
| OpenVPN Monitor | =2.0_rc8 | |
| OpenVPN Monitor | =2.0_rc9 | |
| OpenVPN Monitor | =2.0_rc10 | |
| OpenVPN Monitor | =2.0_rc11 | |
| OpenVPN Monitor | =2.0_rc12 | |
| OpenVPN Monitor | =2.0_rc13 | |
| OpenVPN Monitor | =2.0_rc14 | |
| OpenVPN Monitor | =2.0_rc15 | |
| OpenVPN Monitor | =2.0_rc16 | |
| OpenVPN Monitor | =2.0_rc17 | |
| OpenVPN Monitor | =2.0_rc18 | |
| OpenVPN Monitor | =2.0_rc19 | |
| OpenVPN Monitor | =2.0_rc20 | |
| OpenVPN Monitor | =2.0_rc21 | |
| OpenVPN Monitor | =2.0_test1 | |
| OpenVPN Monitor | =2.0_test2 | |
| OpenVPN Monitor | =2.0_test3 | |
| OpenVPN Monitor | =2.0_test5 | |
| OpenVPN Monitor | =2.0_test6 | |
| OpenVPN Monitor | =2.0_test7 | |
| OpenVPN Monitor | =2.0_test8 | |
| OpenVPN Monitor | =2.0_test9 | |
| OpenVPN Monitor | =2.0_test10 | |
| OpenVPN Monitor | =2.0_test11 | |
| OpenVPN Monitor | =2.0_test12 | |
| OpenVPN Monitor | =2.0_test14 | |
| OpenVPN Monitor | =2.0_test15 | |
| OpenVPN Monitor | =2.0_test16 | |
| OpenVPN Monitor | =2.0_test17 | |
| OpenVPN Monitor | =2.0_test18 | |
| OpenVPN Monitor | =2.0_test19 | |
| OpenVPN Monitor | =2.0_test20 | |
| OpenVPN Monitor | =2.0_test21 | |
| OpenVPN Monitor | =2.0_test22 | |
| OpenVPN Monitor | =2.0_test23 | |
| OpenVPN Monitor | =2.0_test24 | |
| OpenVPN Monitor | =2.0_test26 | |
| OpenVPN Monitor | =2.0_test27 | |
| OpenVPN Monitor | =2.0_test29 |
Never miss a vulnerability like this again
Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.
Reference Links
- http://www.mandriva.com/security/advisories?name=MDKSA-2005:145
- http://www.debian.org/security/2005/dsa-851
- http://openvpn.net/changelog.html
- http://secunia.com/advisories/16463
- http://secunia.com/advisories/17103
- http://www.securityfocus.com/bid/14605
- http://www.novell.com/linux/security/advisories/2005_20_sr.html
Frequently Asked Questions
What is the severity of CVE-2005-2531?
The severity of CVE-2005-2531 is considered high due to the potential for denial of service attacks.
How do I fix CVE-2005-2531?
To fix CVE-2005-2531, upgrade OpenVPN to version 2.0.1 or later.
What versions are affected by CVE-2005-2531?
CVE-2005-2531 affects OpenVPN versions 2.0 beta, rc, and test releases up to 2.0.1.
What causes the vulnerability in CVE-2005-2531?
The vulnerability in CVE-2005-2531 is caused by improper flushing of the OpenSSL error queue when client certificate authentication fails.
Who can exploit CVE-2005-2531?
Remote attackers can exploit CVE-2005-2531 to cause denial of service by targeting clients without proper TLS authentication.
- agent/type
- agent/first-publish-date
- collector/mitre-cve
- source/MITRE
- agent/references
- agent/weakness
- agent/severity
- agent/author
- agent/last-modified-date
- agent/remedy
- agent/description
- agent/event
- agent/source
- agent/softwarecombine
- agent/tags
- collector/nvd-index
- agent/software-canonical-lookup-request
- collector/nvd-historical
- vendor/openvpn
- canonical/openvpn monitor
- version/openvpn monitor/2.0
- version/openvpn monitor/2.0.1_rc1
- version/openvpn monitor/2.0.1_rc2
- version/openvpn monitor/2.0.1_rc3
- version/openvpn monitor/2.0.1_rc4
- version/openvpn monitor/2.0.1_rc5
- version/openvpn monitor/2.0.1_rc6
- version/openvpn monitor/2.0.1_rc7
- version/openvpn monitor/2.0_beta1
- version/openvpn monitor/2.0_beta2
- version/openvpn monitor/2.0_beta3
- version/openvpn monitor/2.0_beta4
- version/openvpn monitor/2.0_beta5
- version/openvpn monitor/2.0_beta6
- version/openvpn monitor/2.0_beta7
- version/openvpn monitor/2.0_beta8
- version/openvpn monitor/2.0_beta9
- version/openvpn monitor/2.0_beta10
- version/openvpn monitor/2.0_beta11
- version/openvpn monitor/2.0_beta12
- version/openvpn monitor/2.0_beta13
- version/openvpn monitor/2.0_beta15
- version/openvpn monitor/2.0_beta16
- version/openvpn monitor/2.0_beta17
- version/openvpn monitor/2.0_beta18
- version/openvpn monitor/2.0_beta19
- version/openvpn monitor/2.0_beta20
- version/openvpn monitor/2.0_beta28
- version/openvpn monitor/2.0_rc1
- version/openvpn monitor/2.0_rc2
- version/openvpn monitor/2.0_rc3
- version/openvpn monitor/2.0_rc4
- version/openvpn monitor/2.0_rc5
- version/openvpn monitor/2.0_rc6
- version/openvpn monitor/2.0_rc7
- version/openvpn monitor/2.0_rc8
- version/openvpn monitor/2.0_rc9
- version/openvpn monitor/2.0_rc10
- version/openvpn monitor/2.0_rc11
- version/openvpn monitor/2.0_rc12
- version/openvpn monitor/2.0_rc13
- version/openvpn monitor/2.0_rc14
- version/openvpn monitor/2.0_rc15
- version/openvpn monitor/2.0_rc16
- version/openvpn monitor/2.0_rc17
- version/openvpn monitor/2.0_rc18
- version/openvpn monitor/2.0_rc19
- version/openvpn monitor/2.0_rc20
- version/openvpn monitor/2.0_rc21
- version/openvpn monitor/2.0_test1
- version/openvpn monitor/2.0_test2
- version/openvpn monitor/2.0_test3
- version/openvpn monitor/2.0_test5
- version/openvpn monitor/2.0_test6
- version/openvpn monitor/2.0_test7
- version/openvpn monitor/2.0_test8
- version/openvpn monitor/2.0_test9
- version/openvpn monitor/2.0_test10
- version/openvpn monitor/2.0_test11
- version/openvpn monitor/2.0_test12
- version/openvpn monitor/2.0_test14
- version/openvpn monitor/2.0_test15
- version/openvpn monitor/2.0_test16
- version/openvpn monitor/2.0_test17
- version/openvpn monitor/2.0_test18
- version/openvpn monitor/2.0_test19
- version/openvpn monitor/2.0_test20
- version/openvpn monitor/2.0_test21
- version/openvpn monitor/2.0_test22
- version/openvpn monitor/2.0_test23
- version/openvpn monitor/2.0_test24
- version/openvpn monitor/2.0_test26
- version/openvpn monitor/2.0_test27
- version/openvpn monitor/2.0_test29