Arch Linux ASA-202012-24 High: OpenSSL Denial Of Service Attack

Arch Linux Security Advisory ASA-202012-24
=========================================
Severity: High
Date    : 2020-12-16
CVE-ID  : CVE-2020-1971
Package : openssl
Type    : denial of service
Remote  : Yes
Link    : https://security.archlinux.org/AVG-1335

Summary
======
The package openssl before version 1.1.1.i-1 is vulnerable to denial of
service.

Resolution
=========
Upgrade to 1.1.1.i-1.

# pacman -Syu "openssl>=1.1.1.i-1"

The problem has been fixed upstream in version 1.1.1.i.

Workaround
=========
None.

Description
==========
A denial of service security issue was discovered in OpenSSL before
1.1.1i. The X.509 GeneralName type is a generic type for representing
different types of names. One of those name types is known as
EDIPartyName. OpenSSL provides a function GENERAL_NAME_cmp which
compares different instances of a GENERAL_NAME to see if they are equal
or not. This function behaves incorrectly when both GENERAL_NAMEs
contain an EDIPARTYNAME. A NULL pointer dereference and a crash may
occur leading to a possible denial of service attack.

Impact
=====
A remote attacker might be able to cause a crash by tricking a
vulnerable client or server into checking a malicious certificate
against a malicious CRL.

References
=========
https://openssl-library.org/news/secadv/20201208.txt
;a=commitdiff;h=f960d81215ebf3f65e03d4d5d857fb9b666d6920
https://security.archlinux.org/CVE-2020-1971