# CVE-2017-3733: Encrypt-Then-Mac renegotiation crash

> A crash in OpenSSL during renegotiation when Encrypt-Then-Mac settings mismatch causes denial of service for clients and servers.

- **Severity:** High 7.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 May 2017
- **Updated:** 16 Sep 2024
- **Also known as:** DEBIAN-CVE-2017-3733, GHSA-6553-6v42-5wqc

## What is CVE-2017-3733?

CVE-2017-3733 is a high-severity denial of service vulnerability in Openssl Openssl, published on 4 May 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

During a renegotiation handshake if the Encrypt-Then-Mac extension is negotiated where it was not in the original handshake (or vice-versa) then this can cause OpenSSL 1.1.0 before 1.1.0e to crash (dependent on ciphersuite). Both clients and servers are affected.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2017-3733?

It affects 2 products.


Products: Hp Operations Agent, Openssl Openssl.

## How do I fix CVE-2017-3733?

Upgrade to a fixed version.

## Is CVE-2017-3733 being exploited?

There is no known exploitation of CVE-2017-3733 in the wild and no public exploit code.

## Other vulnerabilities in Openssl Openssl

- [CVE-2012-2019](https://insights.sbomify.com/CVE-2012-2019/): Other in n/a (critical 10.0)
- [CVE-2012-2020](https://insights.sbomify.com/CVE-2012-2020/): Other in n/a (critical 10.0)
- [CVE-2010-0444](https://insights.sbomify.com/CVE-2010-0444/): Hardcoded credentials in n/a (critical 10.0)
- [CVE-2010-3004](https://insights.sbomify.com/CVE-2010-3004/): Other in n/a (high 7.5)
- [CVE-2010-3005](https://insights.sbomify.com/CVE-2010-3005/): Privilege escalation in n/a (medium 6.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-3733 and fix it if it is affected.

What it is: CVE-2017-3733 is a high-severity denial of service vulnerability in Openssl Openssl, published on 4 May 2017. 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-2017-3733 in the wild and no public exploit code.

Affected product: Openssl Openssl. 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-2017-3733/ (Markdown: https://insights.sbomify.com/CVE-2017-3733/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-3733
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-3733
- OSV: https://osv.dev/vulnerability/CVE-2017-3733

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-3733/
Summaries are generated and may contain mistakes; the official description above is the record.