CVE-2020-17376: Nova OpenStack Nova Live Migration Fails Vulnerability

HIGH
Advisory Identifier: GHSA-c7w7-9c85-4qxv
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CVSS 8.3
CWE-611
Published
Advisory Summary

CVE-2020-17376 is a HIGH (CVSS 8.3) openstack nova live migration fails vulnerability (CWE-611: Improper Restriction of XML External Entity Reference) affecting Nova libraries in the PyPI ecosystem. The issue involves openstack nova live migration fails to update persistent domain xml. Remediation is available by upgrading affected packages to version 19.3.1, 20.3.1.

CVE-2020-17376 at a Glance

CVE Identifier CVE-2020-17376
GHSA Identifier GHSA-c7w7-9c85-4qxv
Severity HIGH
CVSS v3.1 Base Score 8.3
CWE Classification CWE-611: Improper Restriction of XML External Entity Reference
Affected Product Nova
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 8.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability Low (A:L)

How to Fix CVE-2020-17376

To remediate this vulnerability, upgrade all affected Nova dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

nova fixed: 19.3.1 
pip install nova>=19.3.1
nova fixed: 20.3.1 
pip install nova>=20.3.1
nova fixed: Latest secure release 
pip install nova>=Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show nova

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2020-17376, inspect your installed packages using pip:

pip show nova

Analyze the terminal output to locate any version of Nova in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 19.3.1), your application is affected.

Note: The pip show nova command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-611: Improper Restriction of XML External Entity Reference, where the product processes an xml document that can contain xml entities with uris that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output. In Nova, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

An issue was discovered in Guest.migrate in `virt/libvirt/guest.py` in OpenStack Nova before 19.3.1, 20.x before 20.3.1, and 21.0.0. By performing a soft reboot of an instance that has previously undergone live migration, a user may gain access to destination host devices that share the same paths as host devices previously referenced by the virtual machine on the source host. This can include block devices that map to different Cinder volumes at the destination than at the source. Only deployments allowing host-based connections (for instance, root and ephemeral devices) are affected.

CVE-2020-17376 Affected Nova Versions

3 component(s)
Fixed Versions:
19.3.120.3.1
Product / Package Ecosystem Affected Versions Fixed Version
nova
pypi/nova
PyPI
< 19.3.1
19.3.1
nova
pypi/nova
PyPI
≥ 20.0.0
< 20.3.1
20.3.1
nova
pypi/nova
PyPI
21.0.0
All 1 versions
21.0.0
None specified

References

NVD — CVE-2020-17376 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-17376
Security Fix Commit FIX COMMIT
https://github.com/openstack/nova/commit/1bb8ee95d4c3ddc3f607ac57526b75af1b7fbcff
Security Fix Commit FIX COMMIT
https://github.com/openstack/nova/commit/2faf17995dd9daa6f0b91e44be43264e447c678d
Security Fix Commit FIX COMMIT
https://github.com/openstack/nova/commit/a721ca5f510ce3c8ef24f22dac9e475b3d7651db
Security Fix Commit FIX COMMIT
https://github.com/openstack/nova/commit/b9ea91d17703f5b324a50727b6503ace0f4e95eb
Security Fix Commit FIX COMMIT
https://github.com/openstack/nova/commit/c438fd9a0eb1903306a53ab44e3ae80660d8a429
Nova Source Repository REPOSITORY
https://github.com/openstack/nova
Nova Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/nova/PYSEC-2020-243.yaml
launchpad.net/bugs/1890501 WEB
https://launchpad.net/bugs/1890501
Nova Security Information SECURITY
https://security.openstack.org/ossa/OSSA-2020-006.html
Nova Security Information SECURITY
http://www.openwall.com/lists/oss-security/2020/08/25/4

Frequently Asked Questions

What is CVE-2020-17376?
CVE-2020-17376 is a security vulnerability in Nova involving OpenStack Nova Live migration fails to update persistent domain XML under CWE-611: Improper Restriction of XML External Entity Reference.
Which Nova versions are affected?
Affected versions include releases prior to 19.3.1, 20.3.1 across affected packages: nova.
What version fixes CVE-2020-17376?
Upgrading to 19.3.1, 20.3.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is nova affected?
Yes, nova is affected in releases prior to 19.3.1, 20.3.1, Latest secure release. Upgrade your dependency to 19.3.1, 20.3.1, Latest secure release or later.
What is the CVSS score of CVE-2020-17376?
CVE-2020-17376 has a CVSS v3.1 base score of 8.3 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L.
What CWE is associated with CVE-2020-17376?
CVE-2020-17376 is classified under CWE-611: Improper Restriction of XML External Entity Reference (The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.).
How can I check PyPI dependencies for CVE-2020-17376?
Run the dependency tree command: 'pip show nova'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c7w7-9c85-4qxv",
  "modified" : "2024-09-26T14:12:53Z",
  "published" : "2022-05-24T17:26:41Z",
  "aliases" : [ "CVE-2020-17376" ],
  "summary" : "OpenStack Nova Live migration fails to update persistent domain XML",
  "details" : "An issue was discovered in Guest.migrate in `virt/libvirt/guest.py` in OpenStack Nova before 19.3.1, 20.x before 20.3.1, and 21.0.0. By performing a soft reboot of an instance that has previously undergone live migration, a user may gain access to destination host devices that share the same paths as host devices previously referenced by the virtual machine on the source host. This can include block devices that map to different Cinder volumes at the destination than at the source. Only deployments allowing host-based connections (for instance, root and ephemeral devices) are affected.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "nova"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "19.3.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "nova"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "20.0.0"
      }, {
        "fixed" : "20.3.1"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "nova"
    },
    "versions" : [ "21.0.0" ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-17376"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openstack/nova/commit/1bb8ee95d4c3ddc3f607ac57526b75af1b7fbcff"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openstack/nova/commit/2faf17995dd9daa6f0b91e44be43264e447c678d"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openstack/nova/commit/a721ca5f510ce3c8ef24f22dac9e475b3d7651db"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openstack/nova/commit/b9ea91d17703f5b324a50727b6503ace0f4e95eb"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/openstack/nova/commit/c438fd9a0eb1903306a53ab44e3ae80660d8a429"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/openstack/nova"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/nova/PYSEC-2020-243.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://launchpad.net/bugs/1890501"
  }, {
    "type" : "WEB",
    "url" : "https://security.openstack.org/ossa/OSSA-2020-006.html"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2020/08/25/4"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-611" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-04-29T10:57:39Z",
    "nvd_published_at" : "2020-08-26T19:15:00Z"
  }
}