OpenVPN ssl_verify_openssl.c extract_x509_field_ssl double free

CVSS Meta Temp Score
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CTI Interest Score
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4.6$0-$5k0.00

Summaryinfo

A vulnerability was found in OpenVPN. It has been classified as problematic. This affects the function extract_x509_field_ssl of the file ssl_verify_openssl.c. This manipulation causes double free. The identification of this vulnerability is CVE-2017-7521. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability classified as problematic was found in OpenVPN (Network Encryption Software) (unknown version). Affected by this vulnerability is the function extract_x509_field_ssl of the file ssl_verify_openssl.c. The manipulation with an unknown input leads to a double free vulnerability. The CWE definition for the vulnerability is CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. As an impact it is known to affect confidentiality. The summary by CVE is:

OpenVPN versions before 2.4.3 and before 2.3.17 are vulnerable to remote denial-of-service due to memory exhaustion caused by memory leaks and double-free issue in extract_x509_extension().

The bug was discovered 06/22/2017. The weakness was shared 06/21/2017 by Guido Vranken with https://guidovranken.wordpress.com as The OpenVPN post-audit bug bonanza as not defined blog post (Website). The advisory is shared at guidovranken.wordpress.com. This vulnerability is known as CVE-2017-7521 since 04/05/2017. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. Responsible for the vulnerability is the following code: 

tmp = ASN1_STRING_to_UTF8(&buf, asn1);
if (tmp <= 0) {    return FAILURE; }

The vulnerability scanner Nessus provides a plugin with the ID 101064 (Amazon Linux AMI : openvpn (ALAS-2017-852)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Amazon Linux Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 196832 (Ubuntu Security Notification for Openvpn Vulnerabilities (USN-3339-1)).

Upgrading eliminates this vulnerability. The upgrade is hosted for download at openvpn.net. A possible mitigation has been published 6 days after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (101064) and SecurityFocus (BID 99230†). The entries VDB-102707, VDB-102708, VDB-102710 and VDB-102711 are related to this item. If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Name

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.8
VulDB Meta Temp Score: 4.7

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.9
NVD Vector: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
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: 101064
Nessus Name: Amazon Linux AMI : openvpn (ALAS-2017-852)
Nessus File: 🔍
Nessus Risk: 🔍
Nessus Family: 🔍
Nessus Context: 🔍

OpenVAS ID: 703900
OpenVAS Name: Debian Security Advisory DSA 3900-1 (openvpn - security update)
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Upgrade: openvpn.net

Timelineinfo

04/05/2017 🔍
06/21/2017 +77 days 🔍
06/21/2017 +0 days 🔍
06/22/2017 +1 days 🔍
06/22/2017 +0 days 🔍
06/27/2017 +5 days 🔍
06/27/2017 +0 days 🔍
06/28/2017 +1 days 🔍
12/29/2020 +1280 days 🔍

Sourcesinfo

Advisory: The OpenVPN post-audit bug bonanza
Researcher: Guido Vranken
Organization: https://guidovranken.wordpress.com
Status: Not defined
Confirmation: 🔍

CVE: CVE-2017-7521 (🔍)
GCVE (CVE): GCVE-0-2017-7521
GCVE (VulDB): GCVE-100-102709

OVAL: 🔍

SecurityFocus: 99230 - OpenVPN Multiple Security Vulnerabilities
SecurityTracker: 1038768

See also: 🔍

Entryinfo

Created: 06/21/2017 17:48
Updated: 12/29/2020 11:11
Changes: 06/21/2017 17:48 (81), 10/19/2019 14:11 (6), 12/29/2020 11:11 (3)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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