ArchLinux: 201806-10: libgcrypt: private key recovery
Summary
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.
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.
References
https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commitdiff;h=9010d1576e278a4274ad3f4aa15776c28f6ba965;hp=7b6c2afd699e889f5f054cc3d202a61bd0ee1dcf https://lists.gnupg.org/pipermail/gnupg-announce/2018q2/000426.html https://security.archlinux.org/CVE-2018-0495
Workaround
None.