# CVE-2021-3309: Security feature bypass in n/a

> Wekan's LDAP module fails to validate server certificates against the trust store, allowing attackers to bypass TLS security checks.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 26 Jan 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-pmg3-799q-7mhw

## What is CVE-2021-3309?

CVE-2021-3309 is a high-severity vulnerability in n/a, published on 26 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

packages/wekan-ldap/server/ldap.js in Wekan before 4.87 can process connections even though they are not authorized by the Certification Authority trust store,

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2021-3309?

It affects 1 product.


Products: Wekan Project Wekan.

## How do I fix CVE-2021-3309?

No fix has been published for CVE-2021-3309 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-3309 being exploited?

There is no known exploitation of CVE-2021-3309 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2026-30843](https://insights.sbomify.com/CVE-2026-30843/): Wekan has Cross-Board IDOR in Custom Fields Update Endpoints (critical 9.3)
- [CVE-2026-30844](https://insights.sbomify.com/CVE-2026-30844/): Wekan Vulnerable to SSRF through Lack of Validation or Filtering in Attachment URL Loading (critical 9.3)
- [CVE-2026-30847](https://insights.sbomify.com/CVE-2026-30847/): Wekan Credential Leak via notificationUsers Publication Exposes Password Hashes and Session Tokens (critical 9.3)
- [CVE-2025-65780](https://insights.sbomify.com/CVE-2025-65780/): Missing authorization in n/a (high 8.8)
- [CVE-2026-30846](https://insights.sbomify.com/CVE-2026-30846/): Wekan Exposes All Global Webhook Integrations through globalwebhooks Publication (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-3309 and fix it if it is affected.

What it is: CVE-2021-3309 is a high-severity vulnerability in n/a, published on 26 Jan 2021. 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-2021-3309 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-2021-3309/ (Markdown: https://insights.sbomify.com/CVE-2021-3309/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-3309
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-3309
- OSV: https://osv.dev/vulnerability/CVE-2021-3309

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-3309/
Summaries are generated and may contain mistakes; the official description above is the record.