oss-sec mailing list archives
Re: Xen Security Advisory 204 - x86: Mishandling of SYSCALL singlestep during emulation
From: <cve-assign () mitre org>
Date: Mon, 19 Dec 2016 11:34:56 -0500
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Xen Security Advisory XSA-204
Xen wrongly raised the exception based on the flags at the start of the instruction.
Guest userspace which can invoke the instruction emulator can use this flaw to escalate its privilege to that of the guest kernel.
A 64-bit guest kernel which uses an IST for #DB handling will most likely mitigate the issue, but will have a single unexpected #DB exception frame to deal with. This in practice means that Linux is not vulnerable.
Use CVE-2016-10013. - -- CVE Assignment Team M/S M300, 202 Burlington Road, Bedford, MA 01730 USA [ A PGP key is available for encrypted communications at http://cve.mitre.org/cve/request_id.html ] -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBCAAGBQJYWAvbAAoJEHb/MwWLVhi2rVQP/jbDygsBkkatt/w7GbxvpCjr IoSo+krkGda29Dgi4pMAcP8zG3KgRso4tJ48z+Jn30+EpO3zgQSLcCfEaB6Vfbcp zZ1wrer8KTvm5ZcV01vncEO/FVvyXX2KZ6h7XuVakOXCRE1+YEPuvdqdc6UyH7aD mctdIVrR6jDzpsLDT6uZM6ahcCwRp6VDmxz0r4195RygOWqkmsVPmM9Q6F/VyG4A KxBAUFIHUYHdu9Hy/s6U3+M8ugzvpeKKkkBuUcDrFvKu/gfeyFisDlG7GgUtFvp0 DRKHzxrE20UQjU7VJBXpfvkSaorWp9IlhsnrXyIJNyTxb1N3UtkYrDJpxXRlar7y Jj/cVdPT7apIWDIRmRxLWqWrvB2dlx+j3NP3z+wETaKBrLNKj8Aq2h/013VR4CZm QMvNQEYhKr+/AdGiVTDeUBsyqAlpp1aXhrvka4Bz1Ws9BAfTdjivGuOn6ab+Zm2U foecT2t7ktS927yD4uAtE/dFqNrGHORFt4Kr6A+akqYMwxmuaItpctsqMTecB09p vXFAnYk4leKzqd5QkDmqqIilTDAhdN9M0K0SJUebiJgRmhxqU0fhrA4I5jzofggh yoKuStjvt0mM3+UQngv56ohPpCjvMxsbPwl8nN8yhwJUx/ncmpWRm74+wece5SuD agwy+ENLZv0fk0rv5BKv =KJsh -----END PGP SIGNATURE-----
Current thread:
- Xen Security Advisory 204 - x86: Mishandling of SYSCALL singlestep during emulation Xen . org security team (Dec 19)
- Re: Xen Security Advisory 204 - x86: Mishandling of SYSCALL singlestep during emulation cve-assign (Dec 19)