Arch Linux Advisory ASA-201812-5 Low: OpenSSL Private Key Exposure Risk

Arch Linux Security Advisory ASA-201812-5
========================================
Severity: Low
Date    : 2018-12-08
CVE-ID  : CVE-2018-0734 CVE-2018-0735
Package : openssl
Type    : private key recovery
Remote  : Yes
Link    : https://security.archlinux.org/AVG-792

Summary
======
The package openssl before version 1.1.1.a-1 is vulnerable to private
key recovery.

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

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

The problems have been fixed upstream in version 1.1.1.a.

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

Description
==========
- CVE-2018-0734 (private key recovery)

A timing vulnerability has been found in DSA signature generation in
openssl versions up to and including 1.1.1, where information is leaked
via a side channel when a BN is resized and could lead to private key
recovery.

- CVE-2018-0735 (private key recovery)

The OpenSSL ECDSA signature algorithm has been shown to be vulnerable
to a timing side channel attack in openssl versions prior to 1.1.1a. An
attacker could use variations in the signing algorithm to recover the
private key.

Impact
=====
A remote attacker might be able to recover a private ECDSA or DSA key
via a timing attack.

References
=========
https://openssl-library.org/news/secadv/20181029.txt
https://openssl-library.org/news/secadv/20181030.txt
https://github.com/openssl/openssl/commit/8abfe72e8c1de1b95f50aa0d9134803b4d00070f
https://github.com/openssl/openssl/pull/7486
https://github.com/openssl/openssl/commit/b1d6d55ece1c26fa2829e2b819b038d7b6d692b4
https://security.archlinux.org/CVE-2018-0734
https://security.archlinux.org/CVE-2018-0735