CVE-2021-38598
OpenStack Neutron vulnerable to hardware address impersonation
OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
9.1
OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
- Record
CVE-2021-38598- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - CVSS 2.0
- 5.8 Medium
AV:N/AC:M/Au:N/C:N/I:P/A:P - Weakness
- CWE-290
- Updated
- 2026-11-02
CVE List No score
OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
- Record
CVE-2021-38598- Updated
- 2026-11-02
EUVDEUVD-2021-0144 No score
OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
- Record
EUVD-2021-0144- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-hvm4-mc7m-22w4
8.8
OpenStack Neutron vulnerable to hardware address impersonation
OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
- Record
GHSA-hvm4-mc7m-22w4- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Weakness
- CWE-863
- Updated
- 2026-11-02
OSV
9.1
OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
- Record
CVE-2021-38598- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-38598
9.1
OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
- Record
DEBIAN-CVE-2021-38598- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Updated
- 2026-11-02
Show 4 moreShow less
OSVGHSA-hvm4-mc7m-22w4
8.8
OpenStack Neutron vulnerable to hardware address impersonation
OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
- Record
GHSA-hvm4-mc7m-22w4- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Weakness
- CWE-863
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-38598
9.1
OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
- Record
UBUNTU-CVE-2021-38598- CVSS 3.1
- 9.1 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Updated
- 2026-11-02
OSVPYSEC-2021-360 No score
OpenStack Neutron before 16.4.1, 17.x before 17.1.3, and 18.0.0 allows hardware address impersonation when the linuxbridge driver with ebtables-nft is used on a Netfilter-based platform. By sending carefully crafted packets, anyone in control of a server instance connected to the virtual switch can impersonate the hardware addresses of other systems on the network, resulting in denial of service or in some cases possibly interception of traffic intended for other destinations.
- Record
PYSEC-2021-360- Updated
- 2026-11-02
OSVUSN-6067-1 No score
neutron vulnerabilities
David Sinquin discovered that OpenStack Neutron incorrectly handled the default Open vSwitch firewall rules. An attacker could possibly use this issue to impersonate the IPv6 addresses of other systems on the network. This issue only affected Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2021-20267)
Jake Yip and Justin Mammarella discovered that OpenStack Neutron incorrectly handled the linuxbridge driver when ebtables-nft is being used. An attacker could possibly use this issue to impersonate the hardware addresss of other systems on the network. This issue only affected Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2021-38598)
Pavel Toporkov discovered that OpenStack Neutron incorrectly handled extra_dhcp_opts values. An attacker could possibly use this issue to reconfigure dnsmasq. This issue only affected Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2021-40085)
Slawek Kaplonski discovered that OpenStack Neutron incorrectly handled the routes middleware. An attacker could possibly use this issue to cause the API worker to consume memory, leading to a denial of service. This issue only affected Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2021-40797)
It was discovered that OpenStack Neutron incorrectly handled certain queries. A remote authenticated user could possibly use this issue to cause resource consumption, leading to a denial of service. (CVE-2022-3277)
- Record
USN-6067-1- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
neutronPyPI |
before 16.4.1 | 16.4.1 |
neutronPyPI |
17.0.0 up to 17.1.3 | 17.1.3 |
neutronPyPI |
18.0.0 to 18.0.0 | None known |
neutronDebian:12 |
before 2:18.1.0-2 | 2:18.1.0-2 |
neutronDebian:13 |
before 2:18.1.0-2 | 2:18.1.0-2 |
neutronDebian:14 |
before 2:18.1.0-2 | 2:18.1.0-2 |
neutronPyPI |
before 16.4.1, plus listed versions 0.010.0.510.0.610.0.711.0.3 Show 45 moreShow less11.0.411.0.511.0.611.0.711.0.812.0.012.0.0.0b312.0.0.0rc112.0.0.0rc212.0.112.0.212.0.312.0.412.0.512.0.612.1.012.1.113.0.013.0.0.0b113.0.0.0b213.0.0.0b313.0.0.0rc113.0.0.0rc213.0.113.0.213.0.313.0.413.0.513.0.613.0.714.0.014.0.0.0b114.0.0.0b214.0.0.0b314.0.0.0rc114.0.114.0.214.0.314.0.414.1.014.2.014.3.014.3.114.4.014.4.1 |
16.4.1 |
neutronPyPI |
17.0.0 up to 17.1.3, plus listed versions 17.1.017.1.117.1.2 |
17.1.3 |
neutronPyPI |
Listed versions 18.0.0 |
None known |
neutronPyPI |
before 16.4.1, 17.0.0 up to 17.1.3, 18.0.0 up to 18.1.0, plus listed versions 0.010.0.510.0.610.0.711.0.3 Show 45 moreShow less11.0.411.0.511.0.611.0.711.0.812.0.012.0.0.0b312.0.0.0rc112.0.0.0rc212.0.112.0.212.0.312.0.412.0.512.0.612.1.012.1.113.0.013.0.0.0b113.0.0.0b213.0.0.0b313.0.0.0rc113.0.0.0rc213.0.113.0.213.0.313.0.413.0.513.0.613.0.714.0.014.0.0.0b114.0.0.0b214.0.0.0b314.0.0.0rc114.0.114.0.214.0.314.0.414.1.014.2.014.3.014.3.114.4.014.4.1 |
16.4.117.1.318.1.0 |
Show 6 moreShow less
| Package | Affected | Fixed |
|---|---|---|
neutronUbuntu:16.04:LTS |
All versions, plus listed versions 2:7.0.0-0ubuntu12:8.0.0~b1-0ubuntu22:8.0.0~b2-0ubuntu42:8.0.0~b2-0ubuntu52:8.0.0~b2-0ubuntu7 Show 20 moreShow less2:8.0.0~b3-0ubuntu12:8.0.0~rc1-0ubuntu12:8.0.0-0ubuntu12:8.1.0-0ubuntu0.16.04.22:8.1.2-0ubuntu12:8.2.0-0ubuntu12:8.3.0-0ubuntu12:8.3.0-0ubuntu1.12:8.3.0-0ubuntu1.22:8.4.0-0ubuntu12:8.4.0-0ubuntu22:8.4.0-0ubuntu32:8.4.0-0ubuntu42:8.4.0-0ubuntu52:8.4.0-0ubuntu62:8.4.0-0ubuntu7.12:8.4.0-0ubuntu7.22:8.4.0-0ubuntu7.32:8.4.0-0ubuntu7.42:8.4.0-0ubuntu7.5 |
None known |
neutronUbuntu:18.04:LTS |
before 2:12.1.1-0ubuntu8.1, plus listed versions 2:11.0.1-0ubuntu12:12.0.0~b1-0ubuntu12:12.0.0~b1-0ubuntu22:12.0.0~b2-0ubuntu12:12.0.0~b3-0ubuntu1 Show 26 moreShow less2:12.0.0~rc1-0ubuntu12:12.0.0~rc2-0ubuntu12:12.0.0-0ubuntu12:12.0.0-0ubuntu1.12:12.0.0-0ubuntu1.22:12.0.0-0ubuntu1.32:12.0.0-0ubuntu1.42:12.0.0-0ubuntu22:12.0.0-0ubuntu32:12.0.1-0ubuntu12:12.0.1-0ubuntu1.12:12.0.2-0ubuntu12:12.0.3-0ubuntu12:12.0.5-0ubuntu12:12.0.5-0ubuntu42:12.0.5-0ubuntu52:12.0.6-0ubuntu12:12.0.6-0ubuntu22:12.0.6-0ubuntu32:12.1.0-0ubuntu12:12.1.1-0ubuntu12:12.1.1-0ubuntu22:12.1.1-0ubuntu32:12.1.1-0ubuntu42:12.1.1-0ubuntu72:12.1.1-0ubuntu8 |
2:12.1.1-0ubuntu8.1 |
neutronUbuntu:20.04:LTS |
before 2:16.4.2-0ubuntu6.2, plus listed versions 2:15.0.0-0ubuntu12:16.0.0~b1~git2019121613.3e8abb9a8f-0ubuntu12:16.0.0~b2~git2020020712.d5b33ffc77-0ubuntu12:16.0.0~b2~git2020020712.d5b33ffc77-0ubuntu32:16.0.0~b3~git2020032420.a0e1b5804e-0ubuntu1 Show 28 moreShow less2:16.0.0~b3~git2020032420.a0e1b5804e-0ubuntu22:16.0.0~b3~git2020032420.a0e1b5804e-0ubuntu32:16.0.0~b3~git2020032420.a0e1b5804e-0ubuntu42:16.0.0~b3~git2020041013.e74c8f8c88-0ubuntu12:16.0.0~b3~git2020041516.5f42488a9a-0ubuntu12:16.0.0~b3~git2020041516.5f42488a9a-0ubuntu22:16.0.0-0ubuntu0.20.04.12:16.0.0-0ubuntu0.20.04.22:16.1.0-0ubuntu12:16.1.0-0ubuntu22:16.2.0-0ubuntu12:16.2.0-0ubuntu22:16.2.0-0ubuntu32:16.3.0-0ubuntu32:16.3.1-0ubuntu12:16.3.1-0ubuntu1.12:16.3.2-0ubuntu22:16.3.2-0ubuntu32:16.4.0-0ubuntu22:16.4.0-0ubuntu32:16.4.1-0ubuntu22:16.4.2-0ubuntu12:16.4.2-0ubuntu22:16.4.2-0ubuntu32:16.4.2-0ubuntu42:16.4.2-0ubuntu52:16.4.2-0ubuntu62:16.4.2-0ubuntu6.1 |
2:16.4.2-0ubuntu6.2 |
neutronUbuntu:18.04:LTS From an advisory covering 5 CVEs |
before 2:12.1.1-0ubuntu8.1, plus listed versions 2:11.0.1-0ubuntu12:12.0.0~b1-0ubuntu12:12.0.0~b1-0ubuntu22:12.0.0~b2-0ubuntu12:12.0.0~b3-0ubuntu1 Show 26 moreShow less2:12.0.0~rc1-0ubuntu12:12.0.0~rc2-0ubuntu12:12.0.0-0ubuntu12:12.0.0-0ubuntu1.12:12.0.0-0ubuntu1.22:12.0.0-0ubuntu1.32:12.0.0-0ubuntu1.42:12.0.0-0ubuntu22:12.0.0-0ubuntu32:12.0.1-0ubuntu12:12.0.1-0ubuntu1.12:12.0.2-0ubuntu12:12.0.3-0ubuntu12:12.0.5-0ubuntu12:12.0.5-0ubuntu42:12.0.5-0ubuntu52:12.0.6-0ubuntu12:12.0.6-0ubuntu22:12.0.6-0ubuntu32:12.1.0-0ubuntu12:12.1.1-0ubuntu12:12.1.1-0ubuntu22:12.1.1-0ubuntu32:12.1.1-0ubuntu42:12.1.1-0ubuntu72:12.1.1-0ubuntu8 |
2:12.1.1-0ubuntu8.1 |
neutronUbuntu:20.04:LTS From an advisory covering 5 CVEs |
before 2:16.4.2-0ubuntu6.2, plus listed versions 2:15.0.0-0ubuntu12:16.0.0~b1~git2019121613.3e8abb9a8f-0ubuntu12:16.0.0~b2~git2020020712.d5b33ffc77-0ubuntu12:16.0.0~b2~git2020020712.d5b33ffc77-0ubuntu32:16.0.0~b3~git2020032420.a0e1b5804e-0ubuntu1 Show 28 moreShow less2:16.0.0~b3~git2020032420.a0e1b5804e-0ubuntu22:16.0.0~b3~git2020032420.a0e1b5804e-0ubuntu32:16.0.0~b3~git2020032420.a0e1b5804e-0ubuntu42:16.0.0~b3~git2020041013.e74c8f8c88-0ubuntu12:16.0.0~b3~git2020041516.5f42488a9a-0ubuntu12:16.0.0~b3~git2020041516.5f42488a9a-0ubuntu22:16.0.0-0ubuntu0.20.04.12:16.0.0-0ubuntu0.20.04.22:16.1.0-0ubuntu12:16.1.0-0ubuntu22:16.2.0-0ubuntu12:16.2.0-0ubuntu22:16.2.0-0ubuntu32:16.3.0-0ubuntu32:16.3.1-0ubuntu12:16.3.1-0ubuntu1.12:16.3.2-0ubuntu22:16.3.2-0ubuntu32:16.4.0-0ubuntu22:16.4.0-0ubuntu32:16.4.1-0ubuntu22:16.4.2-0ubuntu12:16.4.2-0ubuntu22:16.4.2-0ubuntu32:16.4.2-0ubuntu42:16.4.2-0ubuntu52:16.4.2-0ubuntu62:16.4.2-0ubuntu6.1 |
2:16.4.2-0ubuntu6.2 |
neutronUbuntu:22.04:LTS From an advisory covering 5 CVEs |
before 2:20.3.0-0ubuntu1.1, plus listed versions 2:19.0.0-0ubuntu12:19.1.0+git2022030313.b072cbf05f-0ubuntu12:20.0.0-0ubuntu12:20.0.0-0ubuntu22:20.0.0-0ubuntu32:20.1.0-0ubuntu22:20.2.0-0ubuntu12:20.3.0-0ubuntu1 |
2:20.3.0-0ubuntu1.1 |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-38598 is a critical vulnerability (CVSS 9.1) in Openstack Neutron, published August 23, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.22%, the 68th percentile. Fixed in neutron 16.4.1.
References
launchpad.net/bugs/1938670
nvd.nist.gov/vuln/detail/CVE-2021-38598
github.com/openstack/neutron/commit/0a931391d8990f3e654b4bfda24ae4119c609bbf
github.com/openstack/neutron/commit/cc0d28a3e2ccfad6fc2ff24d78f009cbe3992575
opendev.org/openstack/neutron/commit/fafa5dacd5057120562184a734e7345e7c0e9639
github.com/pypa/advisory-database/tree/main/vulns/neutron/PYSEC-2021-360.yaml
Show 12 moreShow less
github.com/advisories/GHSA-hvm4-mc7m-22w4
security-tracker.debian.org/tracker/CVE-2021-38598
github.com/openstack/neutron
ubuntu.com/security/CVE-2021-38598
openwall.com/lists/oss-security/2021/08/17/4
review.opendev.org/c/openstack/neutron/+/785917
ubuntu.com/security/notices/USN-6067-1
cve.org/CVERecord?id=CVE-2021-38598
ubuntu.com/security/CVE-2021-20267
ubuntu.com/security/CVE-2021-40085
ubuntu.com/security/CVE-2021-40797
ubuntu.com/security/CVE-2022-3277
Left out here: 51 versions. The JSON record has them.