CVE-2023-46835 (GCVE-0-2023-46835)
Vulnerability from cvelistv5 – Published: 2024-01-05 16:34 – Updated: 2025-11-04 19:25
VLAI?
Title
x86/AMD: mismatch in IOMMU quarantine page table levels
Summary
The current setup of the quarantine page tables assumes that the
quarantine domain (dom_io) has been initialized with an address width
of DEFAULT_DOMAIN_ADDRESS_WIDTH (48) and hence 4 page table levels.
However dom_io being a PV domain gets the AMD-Vi IOMMU page tables
levels based on the maximum (hot pluggable) RAM address, and hence on
systems with no RAM above the 512GB mark only 3 page-table levels are
configured in the IOMMU.
On systems without RAM above the 512GB boundary
amd_iommu_quarantine_init() will setup page tables for the scratch
page with 4 levels, while the IOMMU will be configured to use 3 levels
only, resulting in the last page table directory (PDE) effectively
becoming a page table entry (PTE), and hence a device in quarantine
mode gaining write access to the page destined to be a PDE.
Due to this page table level mismatch, the sink page the device gets
read/write access to is no longer cleared between device assignment,
possibly leading to data leaks.
Severity ?
5.5 (Medium)
CWE
- CWE-787 - Out-of-bounds Write
Assigner
References
Credits
This issue was discovered by Roger Pau Monné of XenServer.
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2025-11-04T19:25:41.611Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
"shortName": "CVE"
},
"references": [
{
"tags": [
"x_transferred"
],
"url": "https://xenbits.xenproject.org/xsa/advisory-445.html"
},
{
"url": "http://xenbits.xen.org/xsa/advisory-445.html"
}
],
"title": "CVE Program Container"
},
{
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "NONE",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "HIGH",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
"version": "3.1"
}
},
{
"other": {
"content": {
"id": "CVE-2023-46835",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2024-04-12T04:00:28.791183Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-787",
"description": "CWE-787 Out-of-bounds Write",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2025-06-17T16:11:08.422Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unknown",
"product": "Xen",
"vendor": "Xen",
"versions": [
{
"status": "unknown",
"version": "consult Xen advisory XSA-445"
}
]
}
],
"configurations": [
{
"lang": "en",
"value": "All Xen versions supporting PCI passthrough are affected.\n\nOnly x86 AMD systems with IOMMU hardware are vulnerable.\n\nOnly x86 guests which have physical devices passed through to them can\nleverage the vulnerability.\n"
}
],
"credits": [
{
"lang": "en",
"type": "finder",
"value": "This issue was discovered by Roger Pau Monn\u00e9 of XenServer.\n"
}
],
"datePublic": "2023-11-14T12:00:00.000Z",
"descriptions": [
{
"lang": "en",
"value": "The current setup of the quarantine page tables assumes that the\nquarantine domain (dom_io) has been initialized with an address width\nof DEFAULT_DOMAIN_ADDRESS_WIDTH (48) and hence 4 page table levels.\n\nHowever dom_io being a PV domain gets the AMD-Vi IOMMU page tables\nlevels based on the maximum (hot pluggable) RAM address, and hence on\nsystems with no RAM above the 512GB mark only 3 page-table levels are\nconfigured in the IOMMU.\n\nOn systems without RAM above the 512GB boundary\namd_iommu_quarantine_init() will setup page tables for the scratch\npage with 4 levels, while the IOMMU will be configured to use 3 levels\nonly, resulting in the last page table directory (PDE) effectively\nbecoming a page table entry (PTE), and hence a device in quarantine\nmode gaining write access to the page destined to be a PDE.\n\nDue to this page table level mismatch, the sink page the device gets\nread/write access to is no longer cleared between device assignment,\npossibly leading to data leaks.\n"
}
],
"impacts": [
{
"descriptions": [
{
"lang": "en",
"value": "A device in quarantine mode can access data from previous quarantine\npage table usages, possibly leaking data used by previous domains that\nalso had the device assigned.\n"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2024-01-05T16:34:49.531Z",
"orgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
"shortName": "XEN"
},
"references": [
{
"url": "https://xenbits.xenproject.org/xsa/advisory-445.html"
}
],
"title": "x86/AMD: mismatch in IOMMU quarantine page table levels",
"workarounds": [
{
"lang": "en",
"value": "Not passing through physical devices to guests will avoid the\nvulnerability.\n\nNot using quarantine scratch-page mode will avoid the vulnerability,\nbut could result in other issues.\n"
}
]
}
},
"cveMetadata": {
"assignerOrgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
"assignerShortName": "XEN",
"cveId": "CVE-2023-46835",
"datePublished": "2024-01-05T16:34:49.531Z",
"dateReserved": "2023-10-27T07:55:35.331Z",
"dateUpdated": "2025-11-04T19:25:41.611Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"vulnrichment": {
"containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"https://xenbits.xenproject.org/xsa/advisory-445.html\", \"tags\": [\"x_transferred\"]}, {\"url\": \"http://xenbits.xen.org/xsa/advisory-445.html\"}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2025-11-04T19:25:41.611Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 5.5, \"attackVector\": \"LOCAL\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"HIGH\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2023-46835\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2024-04-12T04:00:28.791183Z\"}}}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-787\", \"description\": \"CWE-787 Out-of-bounds Write\"}]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2024-09-04T19:39:54.875Z\"}}], \"cna\": {\"title\": \"x86/AMD: mismatch in IOMMU quarantine page table levels\", \"credits\": [{\"lang\": \"en\", \"type\": \"finder\", \"value\": \"This issue was discovered by Roger Pau Monn\\u00e9 of XenServer.\\n\"}], \"impacts\": [{\"descriptions\": [{\"lang\": \"en\", \"value\": \"A device in quarantine mode can access data from previous quarantine\\npage table usages, possibly leaking data used by previous domains that\\nalso had the device assigned.\\n\"}]}], \"affected\": [{\"vendor\": \"Xen\", \"product\": \"Xen\", \"versions\": [{\"status\": \"unknown\", \"version\": \"consult Xen advisory XSA-445\"}], \"defaultStatus\": \"unknown\"}], \"datePublic\": \"2023-11-14T12:00:00.000Z\", \"references\": [{\"url\": \"https://xenbits.xenproject.org/xsa/advisory-445.html\"}], \"workarounds\": [{\"lang\": \"en\", \"value\": \"Not passing through physical devices to guests will avoid the\\nvulnerability.\\n\\nNot using quarantine scratch-page mode will avoid the vulnerability,\\nbut could result in other issues.\\n\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"The current setup of the quarantine page tables assumes that the\\nquarantine domain (dom_io) has been initialized with an address width\\nof DEFAULT_DOMAIN_ADDRESS_WIDTH (48) and hence 4 page table levels.\\n\\nHowever dom_io being a PV domain gets the AMD-Vi IOMMU page tables\\nlevels based on the maximum (hot pluggable) RAM address, and hence on\\nsystems with no RAM above the 512GB mark only 3 page-table levels are\\nconfigured in the IOMMU.\\n\\nOn systems without RAM above the 512GB boundary\\namd_iommu_quarantine_init() will setup page tables for the scratch\\npage with 4 levels, while the IOMMU will be configured to use 3 levels\\nonly, resulting in the last page table directory (PDE) effectively\\nbecoming a page table entry (PTE), and hence a device in quarantine\\nmode gaining write access to the page destined to be a PDE.\\n\\nDue to this page table level mismatch, the sink page the device gets\\nread/write access to is no longer cleared between device assignment,\\npossibly leading to data leaks.\\n\"}], \"configurations\": [{\"lang\": \"en\", \"value\": \"All Xen versions supporting PCI passthrough are affected.\\n\\nOnly x86 AMD systems with IOMMU hardware are vulnerable.\\n\\nOnly x86 guests which have physical devices passed through to them can\\nleverage the vulnerability.\\n\"}], \"providerMetadata\": {\"orgId\": \"23aa2041-22e1-471f-9209-9b7396fa234f\", \"shortName\": \"XEN\", \"dateUpdated\": \"2024-01-05T16:34:49.531Z\"}}}",
"cveMetadata": "{\"cveId\": \"CVE-2023-46835\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2025-11-04T19:25:41.611Z\", \"dateReserved\": \"2023-10-27T07:55:35.331Z\", \"assignerOrgId\": \"23aa2041-22e1-471f-9209-9b7396fa234f\", \"datePublished\": \"2024-01-05T16:34:49.531Z\", \"assignerShortName\": \"XEN\"}",
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…