# CVE-2024-37886: Nextcloud user_oidc's ID4me does not validate signature or expiration

> Attackers can bypass authentication in Nextcloud's user_oidc app by submitting unsigned or expired ID4me tokens, potentially gaining unauthorized access.

- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 14 Jun 2024
- **Updated:** 2 Aug 2024
- **Also known as:** GHSA-vw5h-29xf-g55g

## What is CVE-2024-37886?

CVE-2024-37886 is a medium-severity authentication bypass vulnerability in nextcloud security-advisories, published on 14 Jun 2024. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

user_oidc app is an OpenID Connect user backend for Nextcloud. An attacker could potentially trick the app into accepting a request that is not signed by the correct server. It is recommended that the Nextcloud user_oidc app is upgraded to 1.3.5, 2.0.0, 3.0.0, 4.0.0 or 5.0.0.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2024-37886?

It affects 1 product.


Products: Nextcloud User Oidc.

## How do I fix CVE-2024-37886?

No fix has been published for CVE-2024-37886 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-37886 being exploited?

There is no known exploitation of CVE-2024-37886 in the wild and no public exploit code.

## Other vulnerabilities in nextcloud security-advisories

- [CVE-2023-32074](https://insights.sbomify.com/CVE-2023-32074/): Nextcloud user_oidc app is missing brute force protection (high 8.0)
- [CVE-2024-37312](https://insights.sbomify.com/CVE-2024-37312/): Nextcloud user_oidc app's ID4me feature is available even when disabled (medium 6.3)
- [CVE-2023-39953](https://insights.sbomify.com/CVE-2023-39953/): Issuer not verified from obtained token in user_oidc (medium 4.8)
- [CVE-2023-28848](https://insights.sbomify.com/CVE-2023-28848/): CSRF protection on user_oidc login returned the expected token in case of an error (medium 4.8)
- [CVE-2026-45284](https://insights.sbomify.com/CVE-2026-45284/): Nextcloud: Wrong condition in the User OIDC app's LdapService allowed deleted LDAP users to authenticate (medium 4.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-37886 and fix it if it is affected.

What it is: CVE-2024-37886 is a medium-severity authentication bypass vulnerability in nextcloud security-advisories, published on 14 Jun 2024. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2024-37886 in the wild and no public exploit code.

Affected product: nextcloud security-advisories. 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-2024-37886/ (Markdown: https://insights.sbomify.com/CVE-2024-37886/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-37886
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-37886
- OSV: https://osv.dev/vulnerability/CVE-2024-37886

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-37886/
Summaries are generated and may contain mistakes; the official description above is the record.