Arch Linux: ASA-201806-10 High: Libgcrypt Private Key Recovery

Arch Linux Security Advisory ASA-201806-10
=========================================
Severity: High
Date    : 2018-06-16
CVE-ID  : CVE-2018-0495
Package : libgcrypt
Type    : private key recovery
Remote  : No
Link    : https://security.archlinux.org/AVG-719

Summary
======
The package libgcrypt before version 1.8.3-1 is vulnerable to private
key recovery.

Resolution
=========
Upgrade to 1.8.3-1.

# pacman -Syu "libgcrypt>=1.8.3-1"

The problem has been fixed upstream in version 1.8.3.

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

Description
==========
An implementation flaw has been discovered in multiple cryptographic
libraries that allows a side-channel based attacker to recover ECDSA or
DSA private keys. When these cryptographic libraries use the private
key to create a signature, such as for a TLS or SSH connection, they
inadvertently leak information through memory caches. An unprivileged
attacker running on the same machine can collect the information from a
few thousand signatures and recover the value of the private key.

Impact
=====
An unprivileged user might be able to retrieve private keys on the
affected host.

References
=========

https://lists.gnupg.org/pipermail/gnupg-announce/2018q2/000426.html
https://security.archlinux.org/CVE-2018-0495