# CVE-2020-35733: Security feature bypass in n/a

> The Erlang SSL application incorrectly accepts invalid certificate chains, allowing attackers to bypass certificate validation mechanisms.

- **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
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Jan 2021
- **Updated:** 4 Aug 2024
- **Also known as:** CLEANSTART-2026-CB96630, DEBIAN-CVE-2020-35733, GHSA-xg86-vxqv-4j86

## What is CVE-2020-35733?

CVE-2020-35733 is a high-severity vulnerability in Fedoraproject Fedora, published on 15 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An issue was discovered in Erlang/OTP before 23.2.2. The ssl application 10.2 accepts and trusts an invalid X.509 certificate chain to a trusted root Certification Authority.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2020-35733?

It affects 2 products.


Products: Erlang Erlang\/Otp, Fedoraproject Fedora.

## How do I fix CVE-2020-35733?

Upgrade to a fixed version.

## Is CVE-2020-35733 being exploited?

There is no known exploitation of CVE-2020-35733 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2022-37026](https://insights.sbomify.com/CVE-2022-37026/): Auth bypass in n/a (critical 9.8)
- [CVE-2016-10253](https://insights.sbomify.com/CVE-2016-10253/): Memory corruption in n/a (critical 9.8)
- [CVE-2026-55953](https://insights.sbomify.com/CVE-2026-55953/): TLS 1.2 and DTLS client accepts unoffered anonymous cipher suite, bypassing server authentication (critical 9.1)
- [CVE-2026-49759](https://insights.sbomify.com/CVE-2026-49759/): Stack buffer overflow in SCTP error cause parsing in inet_drv allows remote VM crash (high 8.8)
- [CVE-2026-58227](https://insights.sbomify.com/CVE-2026-58227/): TLS/DTLS denial of service via unbounded recursion on cross-signed peer certificate chain (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-35733 and fix it if it is affected.

What it is: CVE-2020-35733 is a high-severity vulnerability in Fedoraproject Fedora, published on 15 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-2020-35733 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2020-35733/ (Markdown: https://insights.sbomify.com/CVE-2020-35733/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-35733
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-35733
- OSV: https://osv.dev/vulnerability/CVE-2020-35733

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-35733/
Summaries are generated and may contain mistakes; the official description above is the record.