How severe is CVE-2020-24722?

CVE-2020-24722 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2020-24722 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-24722?

CVE-2020-24722 primarily affects Exposure Notifications Project Exposure Notifications. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-24722?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-24722 published?

CVE-2020-24722 was published on 2020-10-07 and last updated on 2026-06-17.

CVE-2020-24722

CVE-2020-24722 is a medium-severity vulnerability in Exposure Notifications Project Exposure Notifications with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-294.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 2.6
EPSS exploit prediction: 2% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-294
Affected product: Exposure Notifications Project Exposure Notifications
Published: 2020-10-07
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2020-24722?: 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.
How severe is CVE-2020-24722?: CVE-2020-24722 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2020-24722 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-24722?: CVE-2020-24722 primarily affects Exposure Notifications Project Exposure Notifications. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-24722?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-24722 published?: CVE-2020-24722 was published on 2020-10-07 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:exposure_notifications_project:exposure_notifications:*:*:*:*:*:android:*:*
cpe:2.3:a:exposure_notifications_project:exposure_notifications:*:*:*:*:*:iphone_os:*:*

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