CVE-2020-24722

What it is

An issue was discovered in the GAEN (aka Google/Apple Exposure Notifications) protocol through 2020-10-05, as used in COVID-19 applications on Android and iOS. The encrypted metadata block with a TX value lacks a checksum, allowing bitflipping to amplify a contamination attack. This can cause metadata deanonymization and risk-score inflation. NOTE: the vendor's position is "We do not believe that TX power authentication would be a useful defense against relay attacks.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering.

Exploit odds

2.5% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2020-10-07 15:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 03:06 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.5% in the next 30 days (EPSS).
• Severity: 5.9 MEDIUM (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2020-10-07 15:15 UTC

Last modified

2026-06-17 03:06 UTC

Exploit probability

2.5% · EPSS, next 30 days

Weakness

CWE-294

Record status

Modified

Affected

• Exposure Notifications Project Exposure Notifications ≤ 2020-10-05

Attack profile CVSS 3.1 · 5.9

Attack vector

Network

Complexity

High

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

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