Statement on backdoor in xz library

[nia <nia%NetBSD.org@localhost>]

Recently, a backdoor was discovered in the xz compression library.
xz/liblzma are included as a part of NetBSD and used by the project
for distribution of new releases and packages.

The version of xz shipped in all stable (and unstable) versions of
NetBSD predates any code changes by the author of the backdoor.
NetBSD is therefore safe and unaffected by the recent discoveries.

It is believed that the attack only targets Linux/glibc, but checking
this allowed us to rule out any other attempts at compromising the
library by the author.

The version of xz shipped in pkgsrc, however, is affected. Using
xz from pkgsrc is a non-default setting on NetBSD, and requires
explicit opt-in. Most users of NetBSD will not install xz from
pkgsrc because the version from the base system is preferred.
However, users of pkgsrc on other platforms will need to take
precautions.

Regardless of NetBSD being affected or not, the discovery of the
backdoor is a wake-up call and further discussion will be happening
internally over how to proceed.

References:  https://www.openwall.com/lists/oss-security/2024/03/29/4