Skip to content
Heist/ feed
Back to feed
MediumFix available

xen — security advisory

Type: advisorySources: OSVAdvisory ID: DEBIAN-CVE-2021-3308

An issue was discovered in Xen 4.12.3 through 4.12.4 and 4.13.1 through 4.14.x. An x86 HVM guest with PCI pass through devices can force the allocation of all IDT vectors on the system by rebooting itself with MSI or MSI-X capabilities enabled and entries setup. Such reboots will leak any vectors used by the MSI(-X) entries that the guest might had enabled, and hence will lead to vector exhaustion on the system, not allowing further PCI pass through devices to work properly. HVM guests with PCI pass through devices can mount a Denial of Service (DoS) attack affecting the pass through of PCI devices to other guests or the hardware domain. In the latter case, this would affect the entire host.

Products
xen
Affected versions
Not specified
Fixed versions
4.14.1+11-gb0b734a8b3-1
CVEs
CVE-2021-3308
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 00:58 UTC · Revision 1

Source evidence

DEBIAN-CVE-2021-3308

core-osv · Original source

Published 26 Jan 2021, 20:15 UTC

An issue was discovered in Xen 4.12.3 through 4.12.4 and 4.13.1 through 4.14.x. An x86 HVM guest with PCI pass through devices can force the allocation of all IDT vectors on the system by rebooting itself with MSI or MSI-X capabilities enabled and entries setup. Such reboots will leak any vectors used by the MSI(-X) entries that the guest might had enabled, and hence will lead to vector exhaustion on the system, not allowing further PCI pass through devices to work properly. HVM guests with PCI pass through devices can mount a Denial of Service (DoS) attack affecting the pass through of PCI devices to other guests or the hardware domain. In the latter case, this would affect the entire host.

osv:DEBIAN-CVE-2021-3308

xen

Fixed versions: 4.14.1+11-gb0b734a8b3-1

xen

Fixed versions: 4.14.1+11-gb0b734a8b3-1

xen

Fixed versions: 4.14.1+11-gb0b734a8b3-1

Complete source record
{
  "id": "a1d379191afef1bd4de8c14da1ada865841e9cc288e21b6a80d2b80fc945a669",
  "url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-3308",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "DEBIAN-CVE-2021-3308",
    "summary": "An issue was discovered in Xen 4.12.3 through 4.12.4 and 4.13.1 through 4.14.x. An x86 HVM guest with PCI pass through devices can force the allocation of all IDT vectors on the system by rebooting itself with MSI or MSI-X capabilities enabled and entries setup. Such reboots will leak any vectors used by the MSI(-X) entries that the guest might had enabled, and hence will lead to vector exhaustion on the system, not allowing further PCI pass through devices to work properly. HVM guests with PCI pass through devices can mount a Denial of Service (DoS) attack affecting the pass through of PCI devices to other guests or the hardware domain. In the latter case, this would affect the entire host.",
    "evidence": "osv:DEBIAN-CVE-2021-3308",
    "products": [
      {
        "name": {
          "value": "xen",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.14.1+11-gb0b734a8b3-1",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "xen",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.14.1+11-gb0b734a8b3-1",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "xen",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.14.1+11-gb0b734a8b3-1",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "DEBIAN-CVE-2021-3308",
      "aliases": [
        "DEBIAN-CVE-2021-3308"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "4.14.1+11-gb0b734a8b3-1"
                }
              ]
            }
          ],
          "package": {
            "name": "xen",
            "purl": "pkg:deb/debian/xen?arch=source&distro=bookworm",
            "ecosystem": "Debian:12"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3308.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "4.14.1+11-gb0b734a8b3-1"
                }
              ]
            }
          ],
          "package": {
            "name": "xen",
            "purl": "pkg:deb/debian/xen?arch=source&distro=trixie",
            "ecosystem": "Debian:13"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3308.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "4.14.1+11-gb0b734a8b3-1"
                }
              ]
            }
          ],
          "package": {
            "name": "xen",
            "purl": "pkg:deb/debian/xen?arch=source&distro=forky",
            "ecosystem": "Debian:14"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-3308.json"
          },
          "ecosystem_specific": {
            "urgency": "not yet assigned"
          }
        }
      ],
      "modified": "2026-10-23T18:03:59.387456371Z",
      "provider": "osv",
      "upstream": [
        "CVE-2021-3308"
      ],
      "references": [
        "https://security-tracker.debian.org/tracker/CVE-2021-3308"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2021-3308",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 422865,
  "published_at": "2021-01-26T20:15:12.303+00:00"
}