Bug 1189740 (CVE-2020-36477)

Summary:	VUL-0: CVE-2020-36477: mbedtls: The verification of X.509 certificates when matching the expected common name with the actual certificate name is mishandled
Product:	[openSUSE] openSUSE Distribution	Reporter:	Robert Frohl <rfrohl>
Component:	Security	Assignee:	Martin Pluskal <mpluskal>
Status:	NEW ---	QA Contact:	Security Team bot <security-team>
Severity:	Minor
Priority:	P3 - Medium
Version:	Leap 15.2
Target Milestone:	---
Hardware:	Other
OS:	Other
URL:	https://smash.suse.de/issue/307804/
Whiteboard:
Found By:	Security Response Team	Services Priority:
Business Priority:		Blocker:	---
Marketing QA Status:	---	IT Deployment:	---

Description Robert Frohl 2021-08-24 08:41:28 UTC

CVE-2020-36477

An issue was discovered in Mbed TLS before 2.24.0. The verification of X.509
certificates when matching the expected common name (the cn argument of
mbedtls_x509_crt_verify) with the actual certificate name is mishandled: when
the subjecAltName extension is present, the expected name is compared to any
name in that extension regardless of its type. This means that an attacker could
impersonate a 4-byte or 16-byte domain by getting a certificate for the
corresponding IPv4 or IPv6 address (this would require the attacker to control
that IP address, though).

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2020-36477
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-36477
https://github.com/ARMmbed/mbedtls/issues/3498
https://github.com/ARMmbed/mbedtls/releases/tag/v2.24.0
http://www.cvedetails.com/cve/CVE-2020-36477/

Comment 1 Robert Frohl 2021-08-24 08:44:03 UTC

fixed in factory, not sure if relevant for Leap