Qualys discovered a local privilege escalation in OpenBSD's dynamic loader (ld.so). This vulnerability is exploitable in the default installation (via the set-user-ID executable chpass or passwd) and yields full root privileges. They developed a simple proof of concept and successfully tested it against OpenBSD 6.6 (the current release), 6.5, 6.2, and 6.1, on both amd64 and i386; other releases and architectures are probably also exploitable.
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