Show plain JSON{"cve": {"data_type": "CVE", "references": {"reference_data": [{"url": "http://xenbits.xen.org/xsa/advisory-301.html", "name": "http://xenbits.xen.org/xsa/advisory-301.html", "tags": ["Patch", "Vendor Advisory"], "refsource": "MISC"}, {"url": "http://www.openwall.com/lists/oss-security/2019/10/31/4", "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", "Patch", "Third Party Advisory"], "refsource": "MLIST"}, {"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2BQKX7M2RHCWDBKNPX4KEBI3MJIH6AYZ/", "name": "FEDORA-2019-865bb16900", "tags": [], "refsource": "FEDORA"}, {"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/", "name": "FEDORA-2019-376ec5c107", "tags": [], "refsource": "FEDORA"}, {"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/", "name": "FEDORA-2019-cbb732f760", "tags": [], "refsource": "FEDORA"}, {"url": "https://www.debian.org/security/2020/dsa-4602", "name": "DSA-4602", "tags": [], "refsource": "DEBIAN"}, {"url": "https://seclists.org/bugtraq/2020/Jan/21", "name": "20200114 [SECURITY] [DSA 4602-1] xen security update", "tags": [], "refsource": "BUGTRAQ"}, {"url": "https://security.gentoo.org/glsa/202003-56", "name": "GLSA-202003-56", "tags": [], "refsource": "GENTOO"}]}, "data_format": "MITRE", "description": {"description_data": [{"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."}]}, "problemtype": {"problemtype_data": [{"description": [{"lang": "en", "value": "CWE-193"}]}]}, "data_version": "4.0", "CVE_data_meta": {"ID": "CVE-2019-18423", "ASSIGNER": "cve@mitre.org"}}, "impact": {"baseMetricV2": {"cvssV2": {"version": "2.0", "baseScore": 8.5, "accessVector": "NETWORK", "vectorString": "AV:N/AC:M/Au:S/C:C/I:C/A:C", "authentication": "SINGLE", "integrityImpact": "COMPLETE", "accessComplexity": "MEDIUM", "availabilityImpact": "COMPLETE", "confidentialityImpact": "COMPLETE"}, "severity": "HIGH", "acInsufInfo": false, "impactScore": 10.0, "obtainAllPrivilege": false, "exploitabilityScore": 6.8, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}, "baseMetricV3": {"cvssV3": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.8, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.8}}, "publishedDate": "2019-10-31T14:15Z", "configurations": {"nodes": [{"children": [], "operator": "OR", "cpe_match": [{"cpe23Uri": "cpe:2.3:o:xen:xen:*:*:*:*:*:*:arm:*", "cpe_name": [], "vulnerable": true, "versionEndIncluding": "4.12.1", "versionStartIncluding": "4.8"}]}], "CVE_data_version": "4.0"}, "lastModifiedDate": "2020-08-24T17:37Z"}