CVE-2021-22565Network attack vector

Cross-realm code expiration via unscoped UUID lookup

Published Dec 9, 2021 · Updated Sep 16, 2024

Improper access control in Exposure Notifications Verification Server before 1.1.2 allows remote authenticated users to expire other realms' codes. Before 1.1.2, /api/expirecode performed a database-wide UUID lookup without binding the selected verification code to the caller's realm. Reachability requires code-expiration permission and knowledge or guessing of another realm's rotating UUID; successful expiration prevents the patient from uploading TEKs for exposure notifications.

CVSS severity6.5
Medium
EPSS probability0.43%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Exposure Notifications Verification Server before 1.1.2 allows remote authenticated users to expire other realms' codes. Before 1.1.2, /api/expirecode performed a database-wide UUID lookup without binding the selected verification code to the caller's realm. Reachability requires code-expiration permission and knowledge or guessing of another realm's rotating UUID; successful expiration prevents the patient from uploading TEKs for exposure notifications.

The record

CVE
CVE-2021-22565
Published
Dec 9, 2021
Updated
Sep 16, 2024
Vendor
Google
Product
Exposure Notifications Verification Server
Classifications
CWE-284, CWE-1220, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 9, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <1.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Google · Exposure Notifications Verification Serverversion=unspecified <1.1.2

Published CVSS scores

6.5Google Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
5.8NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
CWE-1220Insufficient Granularity of Access Control
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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