CVE-2020-8562 (GCVE-0-2020-8562)
Vulnerability from cvelistv5
Published
2022-02-01 10:33
Modified
2024-09-16 17:08
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition
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.
References
| ► | URL | Tags | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
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Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Kubernetes | Kubernetes |
Version: unspecified < Version: unspecified < Version: unspecified < Version: unspecified < |
{
"containers": {
"adp": [
{
"providerMetadata": {
"dateUpdated": "2024-08-04T10:03:46.172Z",
"orgId": "af854a3a-2127-422b-91ae-364da2661108",
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"references": [
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"url": "https://github.com/kubernetes/kubernetes/issues/101493"
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{
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"url": "https://groups.google.com/g/kubernetes-security-announce/c/-MFX60_wdOY"
},
{
"tags": [
"x_refsource_CONFIRM",
"x_transferred"
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"url": "https://security.netapp.com/advisory/ntap-20220225-0002/"
}
],
"title": "CVE Program Container"
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],
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{
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{
"lessThan": "unspecified",
"status": "unknown",
"version": "next of v1.18.18",
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{
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"version": "unspecified",
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{
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"versionType": "custom"
},
{
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"status": "affected",
"version": "unspecified",
"versionType": "custom"
},
{
"lessThan": "unspecified",
"status": "unknown",
"version": "next of v1.20.6",
"versionType": "custom"
},
{
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"status": "affected",
"version": "unspecified",
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{
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"credits": [
{
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],
"datePublic": "2021-05-04T00:00:00",
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"metrics": [
{
"cvssV3_1": {
"attackComplexity": "HIGH",
"attackVector": "NETWORK",
"availabilityImpact": "NONE",
"baseScore": 2.2,
"baseSeverity": "LOW",
"confidentialityImpact": "LOW",
"integrityImpact": "NONE",
"privilegesRequired": "HIGH",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N",
"version": "3.1"
}
}
],
"problemTypes": [
{
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{
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"description": "CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition",
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],
"providerMetadata": {
"dateUpdated": "2022-02-25T09:06:13",
"orgId": "a6081bf6-c852-4425-ad4f-a67919267565",
"shortName": "kubernetes"
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{
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}
],
"source": {
"defect": [
"https://github.com/kubernetes/kubernetes/issues/101493"
],
"discovery": "EXTERNAL"
},
"title": "Bypass of Kubernetes API Server proxy TOCTOU",
"workarounds": [
{
"lang": "en",
"value": "If this issue affects your clusters\u2019 control planes, you can use dnsmasq for name resolution and configure the min-cache-ttl and neg-ttl parameters to a low non-zero value to enforce cached replies for proxied connections"
}
],
"x_generator": {
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},
"x_legacyV4Record": {
"CVE_data_meta": {
"ASSIGNER": "security@kubernetes.io",
"DATE_PUBLIC": "2021-05-04T16:51:00.000Z",
"ID": "CVE-2020-8562",
"STATE": "PUBLIC",
"TITLE": "Bypass of Kubernetes API Server proxy TOCTOU"
},
"affects": {
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"version": {
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{
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{
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{
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{
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{
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{
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}
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"credit": [
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"value": "Javier Provecho"
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],
"data_format": "MITRE",
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"data_version": "4.0",
"description": {
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}
]
},
"generator": {
"engine": "Vulnogram 0.0.9"
},
"impact": {
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"confidentialityImpact": "LOW",
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],
"discovery": "EXTERNAL"
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"work_around": [
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}
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},
"cveMetadata": {
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"assignerShortName": "kubernetes",
"cveId": "CVE-2020-8562",
"datePublished": "2022-02-01T10:33:00.317144Z",
"dateReserved": "2020-02-03T00:00:00",
"dateUpdated": "2024-09-16T17:08:37.065Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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