{"containers":{"cna":{"affected":[{"product":"n/a","vendor":"n/a","versions":[{"status":"affected","version":"n/a"}]}],"descriptions":[{"lang":"en","value":"An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service via a XENMEM_add_to_physmap hypercall. p2m->max_mapped_gfn is used by the functions p2m_resolve_translation_fault() and p2m_get_entry() to sanity check guest physical frame. The rest of the code in the two functions will assume that there is a valid root table and check that with BUG_ON(). The function p2m_get_root_pointer() will ignore the unused top bits of a guest physical frame. This means that the function p2m_set_entry() will alias the frame. However, p2m->max_mapped_gfn will be updated using the original frame. It would be possible to set p2m->max_mapped_gfn high enough to cover a frame that would lead p2m_get_root_pointer() to return NULL in p2m_get_entry() and p2m_resolve_translation_fault(). Additionally, the sanity check on p2m->max_mapped_gfn is off-by-one allowing \"highest mapped + 1\" to be considered valid. However, p2m_get_root_pointer() will return NULL. The problem could be triggered with a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen version 4.8 and newer are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected."}],"problemTypes":[{"descriptions":[{"description":"n/a","lang":"en","type":"text"}]}],"providerMetadata":{"dateUpdated":"2020-03-26T14:06:21.000Z","orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","shortName":"mitre"},"references":[{"tags":["x_refsource_MISC"],"url":"http://xenbits.xen.org/xsa/advisory-301.html"},{"name":"[oss-security] 20191031 Xen Security Advisory 301 v3 (CVE-2019-18423) - add-to-physmap can be abused to DoS Arm hosts","tags":["mailing-list","x_refsource_MLIST"],"url":"http://www.openwall.com/lists/oss-security/2019/10/31/4"},{"name":"FEDORA-2019-865bb16900","tags":["vendor-advisory","x_refsource_FEDORA"],"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ/"},{"name":"FEDORA-2019-376ec5c107","tags":["vendor-advisory","x_refsource_FEDORA"],"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/"},{"name":"FEDORA-2019-cbb732f760","tags":["vendor-advisory","x_refsource_FEDORA"],"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/"},{"name":"DSA-4602","tags":["vendor-advisory","x_refsource_DEBIAN"],"url":"https://www.debian.org/security/2020/dsa-4602"},{"name":"20200114 [SECURITY] [DSA 4602-1] xen security update","tags":["mailing-list","x_refsource_BUGTRAQ"],"url":"https://seclists.org/bugtraq/2020/Jan/21"},{"name":"GLSA-202003-56","tags":["vendor-advisory","x_refsource_GENTOO"],"url":"https://security.gentoo.org/glsa/202003-56"}],"x_legacyV4Record":{"CVE_data_meta":{"ASSIGNER":"cve@mitre.org","ID":"CVE-2019-18423","STATE":"PUBLIC"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"n/a","version":{"version_data":[{"version_value":"n/a"}]}}]},"vendor_name":"n/a"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service via a XENMEM_add_to_physmap hypercall. p2m->max_mapped_gfn is used by the functions p2m_resolve_translation_fault() and p2m_get_entry() to sanity check guest physical frame. The rest of the code in the two functions will assume that there is a valid root table and check that with BUG_ON(). The function p2m_get_root_pointer() will ignore the unused top bits of a guest physical frame. This means that the function p2m_set_entry() will alias the frame. However, p2m->max_mapped_gfn will be updated using the original frame. It would be possible to set p2m->max_mapped_gfn high enough to cover a frame that would lead p2m_get_root_pointer() to return NULL in p2m_get_entry() and p2m_resolve_translation_fault(). Additionally, the sanity check on p2m->max_mapped_gfn is off-by-one allowing \"highest mapped + 1\" to be considered valid. However, p2m_get_root_pointer() will return NULL. The problem could be triggered with a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen version 4.8 and newer are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected."}]},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"n/a"}]}]},"references":{"reference_data":[{"name":"http://xenbits.xen.org/xsa/advisory-301.html","refsource":"MISC","url":"http://xenbits.xen.org/xsa/advisory-301.html"},{"name":"[oss-security] 20191031 Xen Security Advisory 301 v3 (CVE-2019-18423) - add-to-physmap can be abused to DoS Arm hosts","refsource":"MLIST","url":"http://www.openwall.com/lists/oss-security/2019/10/31/4"},{"name":"FEDORA-2019-865bb16900","refsource":"FEDORA","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ/"},{"name":"FEDORA-2019-376ec5c107","refsource":"FEDORA","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/"},{"name":"FEDORA-2019-cbb732f760","refsource":"FEDORA","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/"},{"name":"DSA-4602","refsource":"DEBIAN","url":"https://www.debian.org/security/2020/dsa-4602"},{"name":"20200114 [SECURITY] [DSA 4602-1] xen security update","refsource":"BUGTRAQ","url":"https://seclists.org/bugtraq/2020/Jan/21"},{"name":"GLSA-202003-56","refsource":"GENTOO","url":"https://security.gentoo.org/glsa/202003-56"}]}}},"adp":[{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-05T01:54:14.432Z"},"title":"CVE Program Container","references":[{"tags":["x_refsource_MISC","x_transferred"],"url":"http://xenbits.xen.org/xsa/advisory-301.html"},{"name":"[oss-security] 20191031 Xen Security Advisory 301 v3 (CVE-2019-18423) - add-to-physmap can be abused to DoS Arm hosts","tags":["mailing-list","x_refsource_MLIST","x_transferred"],"url":"http://www.openwall.com/lists/oss-security/2019/10/31/4"},{"name":"FEDORA-2019-865bb16900","tags":["vendor-advisory","x_refsource_FEDORA","x_transferred"],"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ/"},{"name":"FEDORA-2019-376ec5c107","tags":["vendor-advisory","x_refsource_FEDORA","x_transferred"],"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/"},{"name":"FEDORA-2019-cbb732f760","tags":["vendor-advisory","x_refsource_FEDORA","x_transferred"],"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/"},{"name":"DSA-4602","tags":["vendor-advisory","x_refsource_DEBIAN","x_transferred"],"url":"https://www.debian.org/security/2020/dsa-4602"},{"name":"20200114 [SECURITY] [DSA 4602-1] xen security update","tags":["mailing-list","x_refsource_BUGTRAQ","x_transferred"],"url":"https://seclists.org/bugtraq/2020/Jan/21"},{"name":"GLSA-202003-56","tags":["vendor-advisory","x_refsource_GENTOO","x_transferred"],"url":"https://security.gentoo.org/glsa/202003-56"}]}]},"cveMetadata":{"assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","assignerShortName":"mitre","cveId":"CVE-2019-18423","datePublished":"2019-10-31T13:36:27.000Z","dateReserved":"2019-10-24T00:00:00.000Z","dateUpdated":"2024-08-05T01:54:14.432Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.1"}