Vulnerability · Published Sep 6, 2021 · Assigned by kubernetes
CVE-2021-25737Holes in EndpointSlice Validation Enable Host Network Hijack
Low 2.7
In plain English
A low-severity security flaw in Kubernetes from Kubernetes. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.3% (higher than 71% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)2.7Low
Exploit odds (30 days)1.3%top 28.9% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
A security issue was discovered in Kubernetes where a user may be able to redirect pod traffic to private networks on a Node. Kubernetes already prevents creation of Endpoint IPs in the localhost or link-local range, but the same validation was not performed on EndpointSlice IPs.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | kubernetes | 1.20.5+really1.20.2-1 | DEBIAN-CVE-2021-25737 |
| Debian:13 | kubernetes | 1.20.5+really1.20.2-1 | DEBIAN-CVE-2021-25737 |
| Debian:14 | kubernetes | 1.20.5+really1.20.2-1 | DEBIAN-CVE-2021-25737 |
| Go | k8s.io/kubernetes | 1.21.1 | GHSA-mfv7-gq43-w965 |
| Go | k8s.io/kubernetes | 1.18.19, 1.19.11, 1.20.7, 1.21.1 | GO-2022-0908 |
| Go | k8s.io/kubernetes | 1.18.19 | GHSA-mfv7-gq43-w965 |
| Go | k8s.io/kubernetes | 1.19.11 | GHSA-mfv7-gq43-w965 |
| Go | k8s.io/kubernetes | 1.20.7 | GHSA-mfv7-gq43-w965 |
| Ubuntu:22.04:LTS | kubernetes | no fix listed | UBUNTU-CVE-2021-25737 |
| Ubuntu:24.04:LTS | kubernetes | no fix listed | UBUNTU-CVE-2021-25737 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Kubernetes | Kubernetes | unspecified – through 1.18.18unspecified – through 1.19.10unspecified – through 1.20.6unspecified – through 1.21.0 |
Weakness: CWE-184 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:N
References
- https://groups.google.com/g/kubernetes-security-announce/c/xAiN3924thY x_refsource_MISC
- https://github.com/kubernetes/kubernetes/issues/102106 x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20211004-0004/ x_refsource_CONFIRM