The X509_verify_cert function in crypto/x509/x509_vfy.c in OpenSSL 1.0.1n, 1.0.1o, 1.0.2b, and 1.0.2c does not properly process X.509 Basic Constraints cA values during identification of alternative certificate chains, which allows remote attackers to spoof a Certification Authority role and trigger unintended certificate verifications via a valid leaf certificate.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1793
Reference (s):
- BID:75652
- URL: http://www.securityfocus.com/bid/75652
- BID:91787
- URL: http://www.securityfocus.com/bid/91787
- CISCO:20150710 OpenSSL Alternative Chains Certificate Forgery Vulnerability (July 2015) Affecting Cisco Products