# CVE-2017-3736: Information disclosure in OpenSSL

> A carry propagation bug in OpenSSL's Montgomery squaring may allow attackers to deduce private key information from Diffie-Hellman operations under specific conditions.

- **Severity:** Medium 6.5 (`CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Nov 2017
- **Updated:** 16 Sep 2024
- **Also known as:** ALPINE-CVE-2017-3736, AZL-84296, DEBIAN-CVE-2017-3736, GHSA-72w7-9ghx-p5pg, UBUNTU-CVE-2017-3736

## What is CVE-2017-3736?

CVE-2017-3736 is a medium-severity vulnerability in Openssl Openssl, published on 2 Nov 2017. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

There is a carry propagating bug in the x86_64 Montgomery squaring procedure in OpenSSL before 1.0.2m and 1.1.0 before 1.1.0g. No EC algorithms are affected. Analysis suggests that attacks against RSA and DSA as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH are considered just feasible (although very difficult) because most of the work necessary to deduce information about a private key may be performed offline. The amount of resources required for such an attack would be very significant and likely only accessible to a limited number of attackers. An attacker would additionally need online access to an unpatched system using the target private key in a scenario with persistent DH parameters and a private key that is shared between multiple clients. This only affects processors that support the BMI1, BMI2 and ADX extensions like Intel Broadwell (5th generation) and later or AMD Ryzen.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2017-3736?

It affects 1 product.


Products: Openssl Openssl.

## How do I fix CVE-2017-3736?

Upgrade to a fixed version.

## Is CVE-2017-3736 being exploited?

There is no known exploitation of CVE-2017-3736 in the wild and no public exploit code.

## Other vulnerabilities in Openssl Openssl

- [CVE-2009-3245](https://insights.sbomify.com/CVE-2009-3245/): Null dereference in n/a (critical 10.0)
- [CVE-2006-3738](https://insights.sbomify.com/CVE-2006-3738/): Memory corruption in n/a (critical 10.0)
- [CVE-2026-63073](https://insights.sbomify.com/CVE-2026-63073/): Untrusted Sender DN Used as Format String in CMP Response Validation (critical 9.8)
- [CVE-2016-6309](https://insights.sbomify.com/CVE-2016-6309/): Use after free in n/a (critical 9.8)
- [CVE-2016-0799](https://insights.sbomify.com/CVE-2016-0799/): Integer overflow in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2017-3736 and fix it if it is affected.

What it is: CVE-2017-3736 is a medium-severity vulnerability in Openssl Openssl, published on 2 Nov 2017. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2017-3736 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-2017-3736/ (Markdown: https://insights.sbomify.com/CVE-2017-3736/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2017-3736
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2017-3736
- OSV: https://osv.dev/vulnerability/CVE-2017-3736

---
From sbomify Insights: https://insights.sbomify.com/CVE-2017-3736/
Summaries are generated and may contain mistakes; the official description above is the record.