# CVE-2020-24722: Other in n/a

> Attackers can deanonymize users and inflate risk scores in COVID-19 apps by exploiting missing checksums in the GAEN protocol metadata.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Oct 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-2gfr-hjcw-mr7q

## What is CVE-2020-24722?

CVE-2020-24722 is a medium-severity vulnerability in n/a, published on 7 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-294 (Authentication Bypass by Capture-replay)

## Which versions are affected by CVE-2020-24722?

It affects 1 product.


Products: Exposure Notifications Project Exposure Notifications.

## How do I fix CVE-2020-24722?

No fix has been published for CVE-2020-24722 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-24722 being exploited?

There is no known exploitation of CVE-2020-24722 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-24722 and fix it if it is affected.

What it is: CVE-2020-24722 is a medium-severity vulnerability in n/a, published on 7 Oct 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-24722 in the wild and no public exploit code.

Affected product: n/a. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2020-24722/ (Markdown: https://insights.sbomify.com/CVE-2020-24722/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-24722
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-24722
- OSV: https://osv.dev/vulnerability/CVE-2020-24722

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-24722/
Summaries are generated and may contain mistakes; the official description above is the record.