# CVE-2016-2850: Security feature bypass in n/a

> Remote attackers can bypass TLS security policies to conduct downgrade attacks against applications using the Botan library.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 May 2016
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-q2v2-6g2j-qv56

## What is CVE-2016-2850?

CVE-2016-2850 is a high-severity vulnerability in Fedoraproject Fedora, published on 13 May 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Botan 1.11.x before 1.11.29 does not enforce TLS policy for (1) signature algorithms and (2) ECC curves, which allows remote attackers to conduct downgrade attacks via unspecified vectors.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2016-2850?

It affects 2 products.


Products: Botan Project Botan, Fedoraproject Fedora.

## How do I fix CVE-2016-2850?

No fix has been published for CVE-2016-2850 yet. Limit exposure of the affected software until one is available.

## Is CVE-2016-2850 being exploited?

There is no known exploitation of CVE-2016-2850 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2021-24115](https://insights.sbomify.com/CVE-2021-24115/): Information disclosure in n/a (critical 9.8)
- [CVE-2018-9127](https://insights.sbomify.com/CVE-2018-9127/): Security feature bypass in n/a (critical 9.8)
- [CVE-2015-7826](https://insights.sbomify.com/CVE-2015-7826/): Security feature bypass in n/a (critical 9.8)
- [CVE-2016-6878](https://insights.sbomify.com/CVE-2016-6878/): Other in n/a (critical 9.8)
- [CVE-2016-9132](https://insights.sbomify.com/CVE-2016-9132/): Integer overflow in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-2850 and fix it if it is affected.

What it is: CVE-2016-2850 is a high-severity vulnerability in Fedoraproject Fedora, published on 13 May 2016. 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-2016-2850 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-2016-2850/ (Markdown: https://insights.sbomify.com/CVE-2016-2850/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-2850
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-2850
- OSV: https://osv.dev/vulnerability/CVE-2016-2850

---
From sbomify Insights: https://insights.sbomify.com/CVE-2016-2850/
Summaries are generated and may contain mistakes; the official description above is the record.