# CVE-2017-3737: Other in OpenSSL

> Attackers can bypass encryption/decryption if an application calls SSL_read/write after a handshake failure, leading to data exposure or corruption.

- **Severity:** Medium 5.9 (`CVSS:3.0/AV:N/AC:H/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:** 7 Dec 2017
- **Updated:** 17 Sep 2024
- **Also known as:** ALPINE-CVE-2017-3737, DEBIAN-CVE-2017-3737, GHSA-fwxf-w2h7-9w25, UBUNTU-CVE-2017-3737

## What is CVE-2017-3737?

CVE-2017-3737 is a medium-severity vulnerability in Debian Debian Linux, published on 7 Dec 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

OpenSSL 1.0.2 (starting from version 1.0.2b) introduced an "error state" mechanism. The intent was that if a fatal error occurred during a handshake then OpenSSL would move into the error state and would immediately fail if you attempted to continue the handshake. This works as designed for the explicit handshake functions (SSL_do_handshake(), SSL_accept() and SSL_connect()), however due to a bug it does not work correctly if SSL_read() or SSL_write() is called directly. In that scenario, if the handshake fails then a fatal error will be returned in the initial function call. If SSL_read()/SSL_write() is subsequently called by the application for the same SSL object then it will succeed and the data is passed without being decrypted/encrypted directly from the SSL/TLS record layer. In order to exploit this issue an application bug would have to be present that resulted in a call to SSL_read()/SSL_write() being issued after having already received a fatal error. OpenSSL version 1.0.2b-1.0.2m are affected. Fixed in OpenSSL 1.0.2n. OpenSSL 1.1.0 is not affected.

Weakness: CWE-787 (Out-of-bounds Write), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2017-3737?

It affects 2 products.


Products: Debian Debian Linux, Openssl Openssl.

## How do I fix CVE-2017-3737?

Upgrade to a fixed version.

## Is CVE-2017-3737 being exploited?

There is no known exploitation of CVE-2017-3737 in the wild and no public exploit code.

## Other vulnerabilities in Debian Debian Linux

- [CVE-2015-3306](https://insights.sbomify.com/CVE-2015-3306/): ProFTPD Improper Access Control (critical 10.0, exploited in the wild)
- [CVE-2025-49113](https://insights.sbomify.com/CVE-2025-49113/): RoundCube Webmail Deserialization of Untrusted Data (critical 9.9, exploited in the wild)
- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
- [CVE-2025-39682](https://insights.sbomify.com/CVE-2025-39682/): Linux Kernel Improper Check for Unusual or Exceptional Conditions (critical 9.8, exploited in the wild)
- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-3737 and fix it if it is affected.

What it is: CVE-2017-3737 is a medium-severity vulnerability in Debian Debian Linux, published on 7 Dec 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-2017-3737 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2017-3737/ (Markdown: https://insights.sbomify.com/CVE-2017-3737/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-3737
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-3737
- OSV: https://osv.dev/vulnerability/CVE-2017-3737

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-3737/
Summaries are generated and may contain mistakes; the official description above is the record.