# CVE-2024-23656: Dex 2.37.0 is discarding TLSconfig and always serves deprecated TLS 1.0/1.1 and insecure ciphers


- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 25 Jan 2024
- **Updated:** 3 Jun 2025
- **Also known as:** GHSA-gr79-9v6v-gc9r, GO-2024-2476

## What is CVE-2024-23656?

CVE-2024-23656 is a high-severity vulnerability in dexidp dex, published on 25 Jan 2024. 

### Official description

Dex is an identity service that uses OpenID Connect to drive authentication for other apps. Dex 2.37.0 serves HTTPS with insecure TLS 1.0 and TLS 1.1. `cmd/dex/serve.go` line 425 seemingly sets TLS 1.2 as minimum version, but the whole `tlsConfig` is ignored after `TLS cert reloader` was introduced in v2.37.0. Configured cipher suites are not respected either. This issue is fixed in Dex 2.38.0.

Weakness: CWE-757 (Selection of Less-Secure Algorithm During Negotiation), CWE-326 (Inadequate Encryption Strength)

## Which versions are affected by CVE-2024-23656?

5 open source packages ship an affected version, including github.com/dexidp/dex. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/dexidp/dex` | Go | All versions | None |
| `github.com/dexidp/dex` | Go | All versions | 0.0.0-20240125115555-5bbdb4420254 |
| `github.com/dexidp/dex` | Go | All versions | 0.0.0-20240125115555-5bbdb4420254 |
| `github.com/dexidp/dex` | Go | From 2.37.0 | 2.38.0 |
| `github.com/dexidp/dex` | Go | From 2.37.0 | 2.38.0 |

Products: Linuxfoundation Dex.

## How do I fix CVE-2024-23656?

Upgrade github.com/dexidp/dex to a fixed version for your release line: 0.0.0-20240125115555-5bbdb4420254 or 2.38.0.

## Is CVE-2024-23656 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-23656 exists.

## Other vulnerabilities in dexidp dex

- [CVE-2020-27847](https://insights.sbomify.com/CVE-2020-27847/): Auth bypass in dexidp/dex (critical 9.8)
- [CVE-2022-39222](https://insights.sbomify.com/CVE-2022-39222/): OAuth authorization code exposure in Dex (critical 9.3)
- [CVE-2020-26290](https://insights.sbomify.com/CVE-2020-26290/): Critical security issues in XML encoding in Dex (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-23656 and fix it if it is affected.

What it is: CVE-2024-23656 is a high-severity vulnerability in dexidp dex, published on 25 Jan 2024. 
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-23656 exists.

Affected packages and fixed versions:
- github.com/dexidp/dex (Go): affected all versions; no fix listed
- github.com/dexidp/dex (Go): affected all versions; fixed in 0.0.0-20240125115555-5bbdb4420254
- github.com/dexidp/dex (Go): affected all versions; fixed in 0.0.0-20240125115555-5bbdb4420254
- github.com/dexidp/dex (Go): affected from 2.37.0; fixed in 2.38.0
- github.com/dexidp/dex (Go): affected from 2.37.0; fixed in 2.38.0

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-2024-23656/ (Markdown: https://insights.sbomify.com/CVE-2024-23656/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-23656
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-23656
- OSV: https://osv.dev/vulnerability/CVE-2024-23656

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-23656/
Summaries are generated and may contain mistakes; the official description above is the record.