VMT: add KCSA for CVE-2020-28914

We have fixed them and put the fix in a release. Let's
make the announcement.

Fixes: #187

Signed-off-by: Archana Shinde <archana.m.shinde@intel.com>

VMT/KCSA/KCSA-CVE-2020-28914.md

@@ -0,0 +1,71 @@
+announcement-date: 2020-11-17
+
+id: KCSA-CVE-2020-28914
+
+title: Kata Containers Improper file permissions for read-only volumes
+
+description: An improper file permissions vulnerability affects Kata Containers 
+prior to 1.11.5. When using a Kubernetes host-path volume and mounting 
+either a file or directory into a container as readonly, the file/directory 
+is mounted as read-only inside the container, but is still writable inside 
+the guest. For a container breakout situation, a malicious guest can 
+potentially modify or delete files/directories expected to be read-only.
+
+affected-components:
+
+  - components: `kata-runtime`
+    version: Before v1.11.5
+
+vulnerabilities:
+
+  - CVE-ID: CVE-2020-28914
+
+reporters:
+
+  - name: `Alex Chapman`
+    affiliation: Independent Researcher
+    reported:
+      - CVE-2020-28914
+
+issues:
+
+  links:
+    - https://github.com/kata-containers/runtime/issues/3041
+    - https://github.com/kata-containers/kata-containers/issues/1061
+
+ reviews:
+
+  v2.0.0:
+    - https://github.com/kata-containers/kata-containers/pull/1062
+
+  v1.12.0:
+    - https://github.com/kata-containers/runtime/pull/3048
+
+  v1.11.5:
+    - https://github.com/kata-containers/runtime/pull/3051
+
+  type: GitHub
+
+reproduce:
+
+  - When using a Kubernetes host-path volume and mounting either a file or
+    directory into a container with read-only: true, the file/directory is 
+    mounted as read-only inside the container, but is still writable inside 
+    the guest (but outside of the container).
+
+    In case a container breakout were to occur, a malicious guest will be able to
+    modify or delete files and directories that are expected to be read-only inside
+    the guest.
+    1. Start a pod with a host-path volume passed as read-only to a container within the pod.
+    2. Start a debug shell to get root access within the guest and attempt
+       to write to the read-only volume shared with the guest under 
+       `/run/kata-containers/shared/sandboxes/{pod-id}/{volume}/`
+    3. Though the volume is not writable within the container, the guest will be 
+       able to write to the volume or even delete it.
+
+notes:
+
+  - If the read-only files/directories are shared across multiple 
+    pods on the same node, other pods will be able to see the modified/deleted files/directories.
+    This vulnerability has been fixed in releases 1.12.0, 1.11.5 and 2.0 branch.
+