Improper input validation in Google Exposure Notifications Verification Server
CVE-2021-22538
A privilege escalation vulnerability impacting the Google Exposure Notification Verification Server (versions prior to 0.23.1), allows an attacker who (1) has UserWrite permissions and (2) is using a carefully crafted request or malicious proxy, to create another user with higher privileges than their own. This occurs due to insufficient checks on the allowed set of permissions. The new user creation event would be captured in the Event Log.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.007 (52.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 52.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/google/exposure-notifications-verification-server/security/advisorie… (Third Party Advisory)
- github.com/google/exposure-notifications-verification-server/commit/eb8cf40b12d… (Patch, Third Party Advisory)
- github.com/google/exposure-notifications-verification-server/releases/tag/v0.23… (Third Party Advisory, Release Notes)
- github.com/google/exposure-notifications-verification-server/releases/tag/v0.24… (Third Party Advisory, Release Notes)
Frequently asked questions
- What is CVE-2021-22538?
- CVE-2021-22538 is a medium-severity vulnerability in Google Exposure Notifications Verification Server, classified under Improper Input Validation. CVSS score: 6.3/10. Published 2021-03-31.
- How severe is CVE-2021-22538?
- Medium severity. CVSS v3 base score is 6.3 out of 10.