# CVE-2020-26877: ApiFest OAuth 2.0 Server 0.3.1 does not validate the redirect URI in accordance with RFC 6749 and is susceptible to an open redirector attack.


- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 29 Jun 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-hg6g-fgr6-h93g

## What is CVE-2020-26877?

CVE-2020-26877 is a medium-severity vulnerability in n/a, published on 29 Jun 2022. 

### Official description

ApiFest OAuth 2.0 Server 0.3.1 does not validate the redirect URI in accordance with RFC 6749 and is susceptible to an open redirector attack. Specifically, it directly sends an authorization code to the redirect URI submitted with the authorization request, without checking whether the redirect URI is registered by the client who initiated the request. This allows an attacker to craft a request with a manipulated redirect URI (redirect_uri parameter), which is under the attacker's control, and consequently obtain the leaked authorization code when the server redirects the client to the manipulated redirect URI with an authorization code. NOTE: this is similar to CVE-2019-3778.

Weakness: CWE-601 (URL Redirection to Untrusted Site)

## Which versions are affected by CVE-2020-26877?

It affects 1 product.


Products: Apifest Oauth 2.0 Server.

## How do I fix CVE-2020-26877?

No fix has been published for CVE-2020-26877 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-26877 being exploited?

There is no known exploitation of CVE-2020-26877 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-26877 and fix it if it is affected.

What it is: CVE-2020-26877 is a medium-severity vulnerability in n/a, published on 29 Jun 2022. 
Exploitation: There is no known exploitation of CVE-2020-26877 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-2020-26877/ (Markdown: https://insights.sbomify.com/CVE-2020-26877/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-26877
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-26877
- OSV: https://osv.dev/vulnerability/CVE-2020-26877

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-26877/
Summaries are generated and may contain mistakes; the official description above is the record.