5.9 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N
4.9 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
SINGLE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:S/C:P/I:P/A:N
0.001 Low
EPSS
Percentile
37.4%
Report Submission Form
Use of nginx.ingress.kubernetes.io/auth* annotations results in a file named {namespace}-{ingress}.passwd. If user knows the namespace and ingress of an ingress they want to compromise they need to be able to create a namespace that is some subset of {namespace}-{ingress}. Then they create an ingress with the remainder of the name and a passwd file of their choosing, this overwrites the other namespace’s passwd file and effectively removes the auth layer provided by nginx ingress.
$ kubectl version
Client Version: version.Info{Major:“1”, Minor:“16+”, GitVersion:“v1.16.5-beta.0”, GitCommit:“224be7bdce5a9dd0c2fd0d46b83865648e2fe0ba”, GitTreeState:“archive”, BuildDate:“2019-12-31T22:42:08Z”, GoVersion:“go1.12.13”, Compiler:“gc”, Platform:“linux/amd64”}
Server Version: version.Info{Major:“1”, Minor:“16”, GitVersion:“v1.16.2”, GitCommit:“c97fe5036ef3df2967d086711e6c0c405941e14b”, GitTreeState:“clean”, BuildDate:“2019-10-15T19:09:08Z”, GoVersion:“go1.12.10”, Compiler:“gc”, Platform:“linux/amd64”}
Installed via kubeadm on gentoo (though I don’t think this is relevant to vulnerability).
quay.io/kubernetes-ingress-controller/nginx-ingress-controller:0.26.1
Attacker can override the htpasswd file of another ingress effectively neutralizing the http authentication.
5.9 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
HIGH
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
NONE
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N
4.9 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
MEDIUM
Authentication
SINGLE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
NONE
AV:N/AC:M/Au:S/C:P/I:P/A:N
0.001 Low
EPSS
Percentile
37.4%