Bugzilla – Bug 1070159
VUL-0: CVE-2017-17563: xen: broken x86 shadow mode refcount overflow check (XSA-249)
Last modified: 2018-03-15 06:17:22 UTC
Created attachment 750405 [details] Upstream patch Xen Security Advisory XSA-249 broken x86 shadow mode refcount overflow check *** EMBARGOED UNTIL 2017-12-12 12:00 UTC *** ISSUE DESCRIPTION ================= Pages being used to run x86 guests in shadow mode are reference counted to track their uses. Unfortunately the overflow check when trying to obtain a new reference used a mask one bit wider than the reference count actually is, rendering the entire check ineffective. IMPACT ====== A malicious or buggy guest may cause a hypervisor crash, resulting in a Denial of Service (DoS) affecting the entire host, or cause hypervisor memory corruption. We cannot rule out a guest being able to escalate its privilege. VULNERABLE SYSTEMS ================== Xen versions 4.1 and later are affected. Xen versions 4.0 and earlier are not affected. x86 systems are vulnerable. ARM systems are not vulnerable. Only guests run in shadow mode can exploit the vulnerability. PV guests typically only run in shadow mode during live migration, as well as for features like VM snapshot. Note that save / restore does *not* use shadow mode, and so does not expose this vulnerability. Some downstreams also include a "non-live migration" feature, which also does not use shadow mode (and thus does not expose this vulnerability). HVM guests run in shadow mode on hardware without HAP support, or when HAP is disabled (globally or in the VM configuration file). Live migration does not affect an HVM guest's use of shadow mode. MITIGATION ========== For HVM guest explicitly configured to use shadow paging (e.g. via the `hap=0' xl domain configuration file parameter), changing to HAP (e.g. by setting `hap=1') will avoid exposing the vulnerability to those guests. HAP is the default (in upstream Xen), where the hardware supports it; so this mitigation is only applicable if HAP has been disabled by configuration. For PV guests, avoiding their live migration avoids the vulnerability. RESOLUTION ========== Applying the attached patch resolves this issue. xsa249.patch xen-unstable, Xen 4.9.x ... 4.5.x $ sha256sum xsa249* e99066b0171d4757c6a66e1223aabe01e990de2d0dc50416936e064e6e750d00 xsa249.patch
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CVE-2017-17563 was assigned to this issue.
SUSE-SU-2018:0438-1: An update that solves 10 vulnerabilities and has three fixes is now available. Category: security (important) Bug References: 1027519,1035442,1051729,1061081,1067317,1068032,1070158,1070159,1070160,1070163,1074562,1076116,1076180 CVE References: CVE-2017-15595,CVE-2017-17563,CVE-2017-17564,CVE-2017-17565,CVE-2017-17566,CVE-2017-18030,CVE-2017-5715,CVE-2017-5753,CVE-2017-5754,CVE-2018-5683 Sources used: SUSE Linux Enterprise Software Development Kit 12-SP3 (src): xen-4.9.1_08-3.26.1 SUSE Linux Enterprise Server 12-SP3 (src): xen-4.9.1_08-3.26.1 SUSE Linux Enterprise Desktop 12-SP3 (src): xen-4.9.1_08-3.26.1 SUSE CaaS Platform ALL (src): xen-4.9.1_08-3.26.1
openSUSE-SU-2018:0459-1: An update that solves 10 vulnerabilities and has three fixes is now available. Category: security (important) Bug References: 1027519,1035442,1051729,1061081,1067317,1068032,1070158,1070159,1070160,1070163,1074562,1076116,1076180 CVE References: CVE-2017-15595,CVE-2017-17563,CVE-2017-17564,CVE-2017-17565,CVE-2017-17566,CVE-2017-18030,CVE-2017-5715,CVE-2017-5753,CVE-2017-5754,CVE-2018-5683 Sources used: openSUSE Leap 42.3 (src): xen-4.9.1_08-16.1
SUSE-SU-2018:0472-1: An update that solves 10 vulnerabilities and has two fixes is now available. Category: security (important) Bug References: 1027519,1035442,1051729,1061081,1068032,1070158,1070159,1070160,1070163,1074562,1076116,1076180 CVE References: CVE-2017-15595,CVE-2017-17563,CVE-2017-17564,CVE-2017-17565,CVE-2017-17566,CVE-2017-18030,CVE-2017-5715,CVE-2017-5753,CVE-2017-5754,CVE-2018-5683 Sources used: SUSE Linux Enterprise Software Development Kit 12-SP2 (src): xen-4.7.4_06-43.24.1 SUSE Linux Enterprise Server 12-SP2 (src): xen-4.7.4_06-43.24.1 SUSE Linux Enterprise Desktop 12-SP2 (src): xen-4.7.4_06-43.24.1
SUSE-SU-2018:0601-1: An update that solves 10 vulnerabilities and has three fixes is now available. Category: security (important) Bug References: 1027519,1035442,1061081,1068032,1070158,1070159,1070160,1070163,1074562,1076116,1076180,1080635,1080662 CVE References: CVE-2017-15595,CVE-2017-17563,CVE-2017-17564,CVE-2017-17565,CVE-2017-17566,CVE-2017-18030,CVE-2017-5715,CVE-2017-5753,CVE-2017-5754,CVE-2018-5683 Sources used: SUSE Linux Enterprise Server 12-LTSS (src): xen-4.4.4_28-22.62.1
SUSE-SU-2018:0609-1: An update that solves 10 vulnerabilities and has two fixes is now available. Category: security (important) Bug References: 1035442,1061081,1068032,1070158,1070159,1070160,1070163,1074562,1076116,1076180,1080635,1080662 CVE References: CVE-2017-15595,CVE-2017-17563,CVE-2017-17564,CVE-2017-17565,CVE-2017-17566,CVE-2017-18030,CVE-2017-5715,CVE-2017-5753,CVE-2017-5754,CVE-2018-5683 Sources used: SUSE OpenStack Cloud 6 (src): xen-4.5.5_24-22.43.1 SUSE Linux Enterprise Server for SAP 12-SP1 (src): xen-4.5.5_24-22.43.1 SUSE Linux Enterprise Server 12-SP1-LTSS (src): xen-4.5.5_24-22.43.1
SUSE-SU-2018:0638-1: An update that solves 10 vulnerabilities and has four fixes is now available. Category: security (important) Bug References: 1027519,1031382,1035442,1061081,1068032,1070158,1070159,1070160,1070163,1074562,1076116,1076180,1080635,1080662 CVE References: CVE-2017-15595,CVE-2017-17563,CVE-2017-17564,CVE-2017-17565,CVE-2017-17566,CVE-2017-18030,CVE-2017-5715,CVE-2017-5753,CVE-2017-5754,CVE-2018-5683 Sources used: SUSE Linux Enterprise Software Development Kit 11-SP4 (src): xen-4.4.4_28-61.23.2 SUSE Linux Enterprise Server 11-SP4 (src): xen-4.4.4_28-61.23.2 SUSE Linux Enterprise Debuginfo 11-SP4 (src): xen-4.4.4_28-61.23.2
SUSE-SU-2018:0678-1: An update that fixes 14 vulnerabilities is now available. Category: security (important) Bug References: 1024307,1030144,1061081,1068032,1070158,1070159,1070160,1070163,1074562,1076116,1076180,1080635,1080662 CVE References: CVE-2017-11334,CVE-2017-15595,CVE-2017-17563,CVE-2017-17564,CVE-2017-17565,CVE-2017-17566,CVE-2017-18030,CVE-2017-5715,CVE-2017-5753,CVE-2017-5754,CVE-2017-5898,CVE-2018-5683,CVE-2018-7540,CVE-2018-7541 Sources used: SUSE Linux Enterprise Server 11-SP3-LTSS (src): xen-4.2.5_21-45.19.1 SUSE Linux Enterprise Point of Sale 11-SP3 (src): xen-4.2.5_21-45.19.1 SUSE Linux Enterprise Debuginfo 11-SP3 (src): xen-4.2.5_21-45.19.1
looks like all are released