CVE-2020-8834

{"id": "CVE-2020-8834", "metrics": {"cvssMetricV2": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"version": "2.0", "baseScore": 4.9, "accessVector": "LOCAL", "vectorString": "AV:L/AC:L/Au:N/C:N/I:N/A:C", "authentication": "NONE", "integrityImpact": "NONE", "accessComplexity": "LOW", "availabilityImpact": "COMPLETE", "confidentialityImpact": "NONE"}, "acInsufInfo": false, "impactScore": 6.9, "baseSeverity": "MEDIUM", "obtainAllPrivilege": false, "exploitabilityScore": 3.9, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 4.0, "exploitabilityScore": 2.0}, {"type": "Secondary", "source": "security@ubuntu.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 4.0, "exploitabilityScore": 2.0}]}, "published": "2020-04-09T22:15:12.050", "references": [{"url": "http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00035.html", "tags": ["Mailing List", "Third Party Advisory"], "source": "security@ubuntu.com"}, {"url": "https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1867717", "tags": ["Exploit", "Third Party Advisory"], "source": "security@ubuntu.com"}, {"url": "https://usn.ubuntu.com/4318-1/", "tags": ["Third Party Advisory"], "source": "security@ubuntu.com"}, {"url": "https://usn.ubuntu.com/usn/usn-4318-1", "tags": ["Third Party Advisory"], "source": "security@ubuntu.com"}, {"url": "https://www.openwall.com/lists/oss-security/2020/04/06/2", "tags": ["Mailing List", "Third Party Advisory"], "source": "security@ubuntu.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-362"}]}, {"type": "Secondary", "source": "security@ubuntu.com", "description": [{"lang": "en", "value": "CWE-368"}]}], "descriptions": [{"lang": "en", "value": "KVM in the Linux kernel on Power8 processors has a conflicting use of HSTATE_HOST_R1 to store r1 state in kvmppc_hv_entry plus in kvmppc_{save,restore}_tm, leading to a stack corruption. Because of this, an attacker with the ability run code in kernel space of a guest VM can cause the host kernel to panic. There were two commits that, according to the reporter, introduced the vulnerability: f024ee098476 (\"KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures\") 87a11bb6a7f7 (\"KVM: PPC: Book3S HV: Work around XER[SO] bug in fake suspend mode\") The former landed in 4.8, the latter in 4.17. This was fixed without realizing the impact in 4.18 with the following three commits, though it's believed the first is the only strictly necessary commit: 6f597c6b63b6 (\"KVM: PPC: Book3S PR: Add guest MSR parameter for kvmppc_save_tm()/kvmppc_restore_tm()\") 7b0e827c6970 (\"KVM: PPC: Book3S HV: Factor fake-suspend handling out of kvmppc_save/restore_tm\") 009c872a8bc4 (\"KVM: PPC: Book3S PR: Move kvmppc_save_tm/kvmppc_restore_tm to separate file\")"}, {"lang": "es", "value": "KVM en el kernel de Linux en los procesadores Power8, presenta un uso conflictivo de HSTATE_HOST_R1 para almacenar el estado r1 en plus kvmppc_hv_entry en kvmppc_ {save, restore} _tm, conllevando a una corrupci\u00f3n de la pila. Debido a esto, un atacante con la capacidad de ejecutar c\u00f3digo en el espacio del kernel de una M\u00e1quina Virtual invitada puede causar que el kernel del host entre en p\u00e1nico. Se presentaron dos commits que, de acuerdo con el reportero, introdujeron la vulnerabilidad: f024ee098476 (\"KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures\") 87a11bb6a7f7 (\"KVM: PPC: Book3S HV: Work around XER[SO] bug in fake suspend mode\") El primero se consigui\u00f3 en la versi\u00f3n 4.8, el \u00faltimo en la versi\u00f3n 4.17. Esto se corrigi\u00f3 sin conocer el impacto en la versi\u00f3n 4.18 con los siguientes tres commits, aunque se cree que el primero es el \u00fanico commit estrictamente necesario: 6f597c6b63b6 (\"KVM: PPC: Book3S PR: Add guest MSR parameter for kvmppc_save_tm()/kvmppc_restore_tm()\") 7b0e827c6970 (\"KVM: PPC: Book3S HV: Factor fake-suspend handling out of kvmppc_save/restore_tm\") 009c872a8bc4 (\"KVM: PPC: Book3S PR: Move kvmppc_save_tm/kvmppc_restore_tm to separate file\")"}], "lastModified": "2022-10-07T15:43:06.733", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "703AF700-7A70-47E2-BC3A-7FD03B3CA9C1"}], "operator": "OR"}, {"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:h:ibm:power8:-:*:*:*:*:*:*:*", "vulnerable": false, "matchCriteriaId": "1227B6B9-593A-4715-BC98-6945670AED37"}], "operator": "OR"}], "operator": "AND"}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*", "vulnerable": true, "matchCriteriaId": "F7016A2A-8365-4F1A-89A2-7A19F2BCAE5B"}, {"criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*", "vulnerable": true, "matchCriteriaId": "23A7C53F-B80F-4E6A-AFA9-58EEA84BE11D"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "B620311B-34A3-48A6-82DF-6F078D7A4493"}], "operator": "OR"}]}], "sourceIdentifier": "security@ubuntu.com"}