| Summary | 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. |
|---|---|
| Publication Date | Feb. 1, 2022, 8:15 p.m. |
| Registration Date | Feb. 2, 2022, 10 a.m. |
| Last Update | Nov. 21, 2024, 2:39 p.m. |
| CVSS3.1 : LOW | |
| スコア | 3.1 |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N |
| 攻撃元区分(AV) | ネットワーク |
| 攻撃条件の複雑さ(AC) | 高 |
| 攻撃に必要な特権レベル(PR) | 低 |
| 利用者の関与(UI) | 不要 |
| 影響の想定範囲(S) | 変更なし |
| 機密性への影響(C) | 低 |
| 完全性への影響(I) | なし |
| 可用性への影響(A) | なし |
| CVSS2.0 : LOW | |
| Score | 3.5 |
|---|---|
| Vector | AV:N/AC:M/Au:S/C:P/I:N/A:N |
| 攻撃元区分(AV) | ネットワーク |
| 攻撃条件の複雑さ(AC) | 中 |
| 攻撃前の認証要否(Au) | 単一 |
| 機密性への影響(C) | 低 |
| 完全性への影響(I) | なし |
| 可用性への影響(A) | なし |
| Get all privileges. | いいえ |
| Get user privileges | いいえ |
| Get other privileges | いいえ |
| User operation required | いいえ |
| Configuration1 | or higher | or less | more than | less than | |
| cpe:2.3:a:kubernetes:kubernetes:1.21.0:*:*:*:*:*:*:* | |||||
| cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:* | 1.20.0 | 1.20.6 | |||
| cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:* | 1.18.18 | ||||
| cpe:2.3:a:kubernetes:kubernetes:*:*:*:*:*:*:*:* | 1.19.0 | 1.19.10 | |||