Overview
- Description
- As mitigations to a report from 2019 and CVE-2020-8555, Kubernetes attempts to prevent proxied connections from accessing link-local or localhost networks when making user-driven connections to Services, Pods, Nodes, or StorageClass service providers. As part of this mitigation Kubernetes does a DNS name resolution check and validates that response IPs are not in the link-local (169.254.0.0/16) or localhost (127.0.0.0/8) range. Kubernetes then performs a second DNS resolution without validation for the actual connection. If a non-standard DNS server returns different non-cached responses, a user may be able to bypass the proxy IP restriction and access private networks on the control plane.
- Source
- jordan@liggitt.net
- NVD status
- Analyzed
Risk scores
CVSS 3.1
- Type
- Primary
- Base score
- 3.1
- Impact score
- 1.4
- Exploitability score
- 1.6
- Vector string
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
- Severity
- LOW
CVSS 2.0
- Type
- Primary
- Base score
- 3.5
- Impact score
- 2.9
- Exploitability score
- 6.8
- Vector string
- AV:N/AC:M/Au:S/C:P/I:N/A:N
Social media
- Hype score
- Not currently trending
Configurations
[
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "7BE1AD99-F12A-4F6E-8EA5-578F32A1F15F",
"versionEndIncluding": "1.18.18"
},
{
"criteria": "cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "34CCC198-AAA6-4DAE-94C4-B8CE55F621F7",
"versionEndIncluding": "1.19.10",
"versionStartIncluding": "1.19.0"
},
{
"criteria": "cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "6868B56F-DDBE-4CDA-9537-A0CAD3CDB1AB",
"versionEndIncluding": "1.20.6",
"versionStartIncluding": "1.20.0"
},
{
"criteria": "cpe:2.3:a:kubernetes:kubernetes:1.21.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "1A3D8AFD-1FB4-4F98-8522-E57A15DD00BB"
}
],
"operator": "OR"
}
]
}
]