CVE-2021-40085
An issue was discovered in OpenStack Neutron before 16.4.1, 17.x before 17.2.1, and 18.x before 18.1.1. Authenticated attackers can reconfigure dnsmasq via a crafted extra_dhcp_opts value.
02 Description
An issue was discovered in OpenStack Neutron before 16.4.1, 17.x before 17.2.1, and 18.x before 18.1.1. Authenticated attackers can reconfigure dnsmasq via a crafted extra_dhcp_opts value.
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 1.83% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 78.5% of scored records. A rank, not a probability.
- NVD base score
- 6.5 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- Important. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-08-31 17:32Z5 YR AGO
- Last updated
- 2024-08-04 02:27Z2 YR AGO
- Reserved
- 2021-08-25
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-20Improper Input ValidationClass
- Data version
- 5.1
- Document digest
- ce1e35485c8242c77e43030e7e3f9c16ef71429030ac97e1d1a941cb698e19ba
05 Affected products
06 References
- launchpad.nethttps://launchpad.net/bugs/1939733
- www.openwall.com[oss-security] 20210831 [OSSA-2021-005] Neutron: Arbitrary dnsmasq reconfiguration via extra_dhcp_opts (CVE-2021-40085)http://www.openwall.com/lists/oss-security/2021/08/31/2
- security.openstack.orghttps://security.openstack.org/ossa/OSSA-2021-005.html
- lists.debian.org[debian-lts-announce] 20211011 [SECURITY] [DLA 2781-1] neutron security updatehttps://lists.debian.org/debian-lts-announce/2021/10/msg00005.html
- www.debian.orgDSA-4983https://www.debian.org/security/2021/dsa-4983
- lists.debian.org[debian-lts-announce] 20220526 [SECURITY] [DLA 3027-1] neutron security updatehttps://lists.debian.org/debian-lts-announce/2022/05/msg00038.html
07 Fixed in
Debian 12
- neutron Fixed in 2:18.1.0-3
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- neutron Fixed in 2:18.1.0-3
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- neutron Fixed in 2:18.1.0-3
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 16.04 LTS
- neutron No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 18.04 LTS
- neutron Fixed in 2:12.1.1-0ubuntu8.1
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 20.04 LTS
- neutron Fixed in 2:16.4.2-0ubuntu6.2
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.