{"id":"CVE-2025-58151","state":"PUBLISHED","title":"varstored: TOCTOU issues with mapped guest memory","description":"varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table.","publishedAt":"2026-07-09T14:45:16.531Z","updatedAt":"2026-07-09T15:41:25.431Z","severity":{"score":9.4,"label":"Critical","version":"4.0","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","source":"XEN"},"assigner":"XEN","products":["Xen varstored"],"affected":[{"vendor":"Xen","product":"varstored","defaultStatus":"unaffected","versions":[{"version":"all","status":"affected"}],"platforms":["Linux"]}],"references":["https://xenbits.xen.org/xsa/advisory-478.html","http://www.openwall.com/lists/oss-security/2026/01/27/2","http://xenbits.xen.org/xsa/advisory-478.html"],"weaknesses":["CWE-367"],"ingestedAt":"2026-10-29T20:09:39.787Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/58xxx/CVE-2025-58151.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-58151","state":"PUBLISHED","datePublished":"2026-07-09T14:45:16.531Z","dateUpdated":"2026-07-09T15:41:25.431Z","assignerShortName":"XEN","assignerOrgId":"23aa2041-22e1-471f-9209-9b7396fa234f","dateReserved":"2025-08-26T06:48:41.444Z"},"containers":{"cna":{"title":"varstored: TOCTOU issues with mapped guest memory","descriptions":[{"lang":"en","value":"varstored is a component of the Xapi toolstack handling UEFI Variables\nfor a VM.  It has a communication path with OVMF inside the VM involving\nmapping a buffer prepared by OVMF.\n\nWithin varstored, there were insufficient compiler barriers, creating\nTOCTOU issues with data in the shared buffer.\n\nThe exact vulnerable behaviour depends on the code generated by the\ncompiler.  In a build of varstored using default settings, the attacker\ncan control an index used in a jump table."}],"affected":[{"vendor":"Xen","product":"varstored","defaultStatus":"unaffected","versions":[{"version":"all","status":"affected"}],"platforms":["Linux"]}],"references":[{"url":"https://xenbits.xen.org/xsa/advisory-478.html"}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"HIGH","subConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","subIntegrityImpact":"HIGH","vulnAvailabilityImpact":"HIGH","subAvailabilityImpact":"HIGH","exploitMaturity":"NOT_DEFINED","Safety":"NOT_DEFINED","Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","valueDensity":"NOT_DEFINED","vulnerabilityResponseEffort":"NOT_DEFINED","providerUrgency":"NOT_DEFINED","version":"4.0","baseSeverity":"CRITICAL","baseScore":9.4,"vectorString":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-367","lang":"en","description":"CWE-367 Time-of-check time-of-use (TOCTOU) race condition","type":"CWE"}]}],"providerMetadata":{"shortName":"XEN","orgId":"23aa2041-22e1-471f-9209-9b7396fa234f","dateUpdated":"2026-07-09T14:45:16.531Z"},"datePublic":"2026-01-27T13:00:00.000Z","impacts":[{"capecId":"CAPEC-233","descriptions":[{"lang":"en","value":"CAPEC-233 Privilege Escalation"}]}],"credits":[{"lang":"en","value":"This issue was discovered by Teddy Astie of Vates.","type":"finder"}],"source":{"discovery":"UNKNOWN"},"x_generator":{"engine":"Vulnogram 1.0.2"}},"adp":[{"title":"CVE Program Container","references":[{"url":"http://www.openwall.com/lists/oss-security/2026/01/27/2"},{"url":"http://xenbits.xen.org/xsa/advisory-478.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-07-09T15:05:08.753Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-09T15:40:36.292177Z","id":"CVE-2025-58151","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-09T15:41:25.431Z"}}]}}}