# CVE-2020-26254: omniauth-apple allows attacker to fake their email address during authentication

> Attackers can spoof email addresses during Apple Sign-In, potentially leading to account takeover in applications relying on email for identification.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Dec 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-49r3-2549-3633

## What is CVE-2020-26254?

CVE-2020-26254 is a high-severity authentication bypass vulnerability in nhosoya omniauth-apple, published on 8 Dec 2020. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

omniauth-apple is the OmniAuth strategy for "Sign In with Apple" (RubyGem omniauth-apple). In omniauth-apple before version 1.0.1 attackers can fake their email address during authentication. This vulnerability impacts applications using the omniauth-apple strategy of OmniAuth and using the info.email field of OmniAuth's Auth Hash Schema for any kind of identification. The value of this field may be set to any value of the attacker's choice including email addresses of other users. Applications not using info.email for identification but are instead using the uid field are not impacted in the same manner. Note, these applications may still be negatively affected if the value of info.email is being used for other purposes. Applications using affected versions of omniauth-apple are advised to upgrade to omniauth-apple version 1.0.1 or later.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2020-26254?

2 open source packages ship an affected version, including omniauth-apple. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `omniauth-apple` | RubyGems | All versions | 1.0.1 |
| `omniauth-apple` | RubyGems | All versions | 1.0.1 |

Products: Omniauth-Apple Project Omniauth-Apple.

## How do I fix CVE-2020-26254?

Upgrade omniauth-apple to 1.0.1 or later.

## Is CVE-2020-26254 being exploited?

There is no known exploitation of CVE-2020-26254 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-26254 and fix it if it is affected.

What it is: CVE-2020-26254 is a high-severity authentication bypass vulnerability in nhosoya omniauth-apple, published on 8 Dec 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-26254 in the wild and no public exploit code.

Affected packages and fixed versions:
- omniauth-apple (RubyGems): affected all versions; fixed in 1.0.1
- omniauth-apple (RubyGems): affected all versions; fixed in 1.0.1

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-2020-26254/ (Markdown: https://insights.sbomify.com/CVE-2020-26254/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-26254
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-26254
- OSV: https://osv.dev/vulnerability/CVE-2020-26254

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-26254/
Summaries are generated and may contain mistakes; the official description above is the record.