CVE-2021-25740 Holes in EndpointSlice Validation Enable Host Network Hijack
Attackers can hijack host network traffic via confused deputy attacks in EndpointSlice validation, bypassing network restrictions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-25740?
CVE-2021-25740 is a low-severity server-side request forgery vulnerability in Kubernetes Kubernetes, published on 20 Sep 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A security issue was discovered with Kubernetes that could enable users to send network traffic to locations they would otherwise not have access to via a confused deputy attack.
Which versions are affected by CVE-2021-25740?
2 open source packages ship an affected version, including k8s.io/kubernetes. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
k8s.io/kubernetes Go | All versions to 1.22.2 | None |
k8s.io/kubernetes Go | All versions to 1.22.2 | None |
Products include Kubernetes Kubernetes.
How do I fix CVE-2021-25740?
Apply the vendor's patch.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2021-25740 being exploited?
There is no known exploitation of CVE-2021-25740 in the wild and no public exploit code.
Other vulnerabilities in Kubernetes Kubernetes
- CVE-2018-1002105 Privilege Escalation in Kubernetes
- CVE-2017-1000056 Kubernetes Privilege Escalation
- CVE-2016-1906 Authorization bypass in Openshift
- CVE-2023-3676 Kubernetes - Windows nodes - Insufficient input sanitization leads to privilege escalation
- CVE-2023-3955 Kubernetes - Windows nodes - Insufficient input sanitization leads to privilege escalation
Sources
Also known as AZL-89312, DEBIAN-CVE-2021-25740, GHSA-vw47-mr44-3jf9, MINI-2hj8-5mrc-xh8c, MINI-2v84-775m-2c3g, MINI-3256-rwg7-g8xr and 10 more.