[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAA8xKjWY2+xo57n8hsvG6yMyhs6nAH+S4NbCsEJLWEVff_aWzg@mail.gmail.com>
Date: Mon, 30 Nov 2020 17:07:43 +0100
From: Mauro Matteo Cascella <mcascell@...hat.com>
To: oss-security@...ts.openwall.com
Cc: xen-announce@...ts.xen.org, xen-devel@...ts.xen.org,
xen-users@...ts.xen.org,
"Xen.org security team" <security-team-members@....org>
Subject: Re: Xen Security Advisory 355 v2 - stack corruption
from XSA-346 change
Hello,
Has a CVE been assigned for this issue?
Regards,
On Tue, Nov 24, 2020 at 1:06 PM Xen.org security team <security@....org> wrote:
>
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA256
>
> Xen Security Advisory XSA-355
> version 2
>
> stack corruption from XSA-346 change
>
> UPDATES IN VERSION 2
> ====================
>
> Added metadata file.
>
> Public release.
>
> ISSUE DESCRIPTION
> =================
>
> One of the two changes for XSA-346 introduced an on-stack array. The
> check for guarding against overrunning this array was off by one,
> allowing for corruption of the first stack slot immediately following
> this array.
>
> IMPACT
> ======
>
> A malicious or buggy HVM or PVH guest can cause Xen to crash, resulting
> in a Denial of Service (DoS) to the entire host. Privilege escalation
> as well as information leaks cannot be excluded.
>
> VULNERABLE SYSTEMS
> ==================
>
> All Xen versions which have the patches for XSA-346 applied are
> vulnerable.
>
> Only x86 HVM and PVH guests can leverage the vulnerability. Arm guests
> and x86 PV guests cannot leverage the vulnerability.
>
> Only x86 HVM and PVH guests which have physical devices passed through
> to them can leverage the vulnerability.
>
> MITIGATION
> ==========
>
> Not passing through physical devices to untrusted guests will avoid
> the vulnerability.
>
> CREDITS
> =======
>
> This issue was discovered by Jan Beulich of SUSE.
>
> RESOLUTION
> ==========
>
> Applying the attached patch resolves this issue.
>
> Note that patches for released versions are generally prepared to
> apply to the stable branches, and may not apply cleanly to the most
> recent release tarball. Downstreams are encouraged to update to the
> tip of the stable branch before applying these patches.
>
> xsa355.patch xen-unstable - Xen 4.10.x
>
> $ sha256sum xsa355*
> a93bfc376897e7cffd095d395f1a66476adb9503d7d80a59b7861e64c2675323 xsa355.meta
> dae633c11cf2eff3e304737265e18ab09213e8e4640458080a944ae7a40819a4 xsa355.patch
> $
>
> NOTE CONCERNING SHORT EMBARGO
> =============================
>
> This issue is likely to be re-discovered as the changes for XSA-346
> are deployed more widely, since the issue is also triggerable without
> any malice or bugginess.
>
> DEPLOYMENT DURING EMBARGO
> =========================
>
> Deployment of the patches and/or mitigations described above (or
> others which are substantially similar) is permitted during the
> embargo, even on public-facing systems with untrusted guest users and
> administrators.
>
> But: Distribution of updated software is prohibited (except to other
> members of the predisclosure list).
>
> Predisclosure list members who wish to deploy significantly different
> patches and/or mitigations, please contact the Xen Project Security
> Team.
>
> (Note: this during-embargo deployment notice is retained in
> post-embargo publicly released Xen Project advisories, even though it
> is then no longer applicable. This is to enable the community to have
> oversight of the Xen Project Security Team's decisionmaking.)
>
> For more information about permissible uses of embargoed information,
> consult the Xen Project community's agreed Security Policy:
> http://www.xenproject.org/security-policy.html
> -----BEGIN PGP SIGNATURE-----
>
> iQFABAEBCAAqFiEEI+MiLBRfRHX6gGCng/4UyVfoK9kFAl+89pEMHHBncEB4ZW4u
> b3JnAAoJEIP+FMlX6CvZRHQH/1D8CfjZWYgLcdYOg6sDO6BIK8IsnAiOoe2C8b9i
> M8QPFzHlUx09FI5CHVb0Va/pFliR1OS2tmmIU30DL9nmiDLcaP2uvpgJAYo5GwL5
> Rzccjo4qbXwfSRQvHmLzbr+XN8sHDxbekpFd8T5WvuarUgxOaPCLTfSG0nag/t52
> OVNIdDcP5lSt/Z88lYW75j4gBAsXUZDEXgn81JpeHj9js8YLFC3WFcwh58Jjd+hw
> 5DH955jNAKD8TRSy6uffDpvN1m9wm2vDGeXSUcJyswlV8Nqi6YRW4XO4Q6Cfj+CG
> LVBS/T977JZGJjRvTw4j0H+xAXiLFwQ1I/6v6fSZzxDMt9k=
> =+4M1
> -----END PGP SIGNATURE-----
--
Mauro Matteo Cascella
Red Hat Product Security
PGP-Key ID: BB3410B0
Powered by blists - more mailing lists
Please check out the
Open Source Software Security Wiki, which is counterpart to this
mailing list.
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
