{"id":"CVE-2023-46839","state":"PUBLISHED","title":"pci: phantom functions assigned to incorrect contexts","description":"PCI devices can make use of a functionality called phantom functions,\nthat when enabled allows the device to generate requests using the IDs\nof functions that are otherwise unpopulated.  This allows a device to\nextend the number of outstanding requests.\n\nSuch phantom functions need an IOMMU context setup, but failure to\nsetup the context is not fatal when the device is assigned.  Not\nfailing device assignment when such failure happens can lead to the\nprimary device being assigned to a guest, while some of the phantom\nfunctions are assigned to a different domain.\n","publishedAt":"2024-03-20T10:35:52.532Z","updatedAt":"2025-11-04T18:18:53.943Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","source":"CISA-ADP"},"assigner":"XEN","products":["Xen Xen"],"affected":[{"vendor":"Xen","product":"Xen","defaultStatus":"unknown","versions":[{"version":"consult Xen advisory XSA-449","status":"unknown"}]}],"references":["https://xenbits.xenproject.org/xsa/advisory-449.html","https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XLL6SQ6IKFYXLYWITYZCRV5IBRK5G35R/","http://xenbits.xen.org/xsa/advisory-449.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:24.729Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/46xxx/CVE-2023-46839.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-46839","state":"PUBLISHED","datePublished":"2024-03-20T10:35:52.532Z","dateUpdated":"2025-11-04T18:18:53.943Z","assignerShortName":"XEN","assignerOrgId":"23aa2041-22e1-471f-9209-9b7396fa234f","dateReserved":"2023-10-27T07:55:35.332Z"},"containers":{"cna":{"title":"pci: phantom functions assigned to incorrect contexts","descriptions":[{"lang":"en","value":"PCI devices can make use of a functionality called phantom functions,\nthat when enabled allows the device to generate requests using the IDs\nof functions that are otherwise unpopulated.  This allows a device to\nextend the number of outstanding requests.\n\nSuch phantom functions need an IOMMU context setup, but failure to\nsetup the context is not fatal when the device is assigned.  Not\nfailing device assignment when such failure happens can lead to the\nprimary device being assigned to a guest, while some of the phantom\nfunctions are assigned to a different domain.\n"}],"affected":[{"vendor":"Xen","product":"Xen","defaultStatus":"unknown","versions":[{"version":"consult Xen advisory XSA-449","status":"unknown"}]}],"references":[{"url":"https://xenbits.xenproject.org/xsa/advisory-449.html"}],"providerMetadata":{"shortName":"XEN","orgId":"23aa2041-22e1-471f-9209-9b7396fa234f","dateUpdated":"2024-03-20T10:35:52.532Z"},"datePublic":"2024-01-30T12:00:00.000Z","impacts":[{"descriptions":[{"lang":"en","value":"Under certain circumstances a malicious guest assigned a PCI device\nwith phantom functions may be able to access memory from a previous\nowner of the device.\n"}]}],"configurations":[{"lang":"en","value":"Systems running all version of Xen are affected.\n\nOnly x86 systems are vulnerable.  Arm systems are not vulnerable.\n\nOnly systems using PCI passthrough of devices with phantom functions\nare affected.\n"}],"workarounds":[{"lang":"en","value":"There is no mitigation (other than not passing through PCI devices\nwith phantom functions to guests).\n"}],"credits":[{"lang":"en","type":"finder","value":"This issue was discovered by Roger Pau Monné of XenServer.\n"}]},"adp":[{"title":"CVE Program Container","references":[{"url":"https://xenbits.xenproject.org/xsa/advisory-449.html","tags":["x_transferred"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/XLL6SQ6IKFYXLYWITYZCRV5IBRK5G35R/"},{"url":"http://xenbits.xen.org/xsa/advisory-449.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-04T18:18:53.943Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":5.3,"attackVector":"NETWORK","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"LOW"}},{"other":{"type":"ssvc","content":{"timestamp":"2024-08-06T14:00:00.793454Z","id":"CVE-2023-46839","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"problemTypes":[{"descriptions":[{"type":"CWE","lang":"en","description":"CWE-noinfo Not enough information"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-11-21T19:17:55.653Z"}}]}}}