Cisco ASA Next-Generation Firewall OpenSSL Alternative Chains Certificate Forgery (cisco-sa-20150710-openssl)

Medium Nessus Plugin ID 86104

Synopsis

The remote security device is missing a vendor-supplied security patch.

Description

The remote ASA Next-Generation Firewall (NGFW) host is missing a security patch. It is, therefore, affected by a certificate validation bypass vulnerability in the bundled version of OpenSSL. The vulnerability exists due to a flaw in the X509_verify_cert() function in x509_vfy.c that is triggered when locating alternate certificate chains when the first attempt to build such a chain fails. A remote attacker can exploit this, by using a valid leaf certificate as a certificate authority (CA), to issue invalid certificates that will bypass authentication.

Solution

Upgrade to the relevant fixed version referenced in Cisco bug ID CSCuv26213.

See Also

http://www.nessus.org/u?3b4e4a60

https://www.openssl.org/news/secadv/20150709.txt

Plugin Details

Severity: Medium

ID: 86104

File Name: cisco-sa-CSCuv26213-asa-cx.nasl

Version: 1.7

Type: local

Family: CISCO

Published: 2015/09/23

Updated: 2018/11/15

Dependencies: 12634

Risk Information

Risk Factor: Medium

CVSS v2.0

Base Score: 6.4

Temporal Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

Temporal Vector: CVSS2#E:POC/RL:OF/RC:C

Vulnerability Information

CPE: cpe:/h:cisco:adaptive_security_appliance, cpe:/a:openssl:openssl

Required KB Items: Host/Cisco/ASA-CX/Version

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 2015/09/15

Vulnerability Publication Date: 2015/07/09

Reference Information

CVE: CVE-2015-1793

BID: 75652

CISCO-BUG-ID: CSCuv26213

CISCO-SA: cisco-sa-20150710-openssl