# CVE-2020-11939: Integer overflow in n/a

> Integer overflows in nDPI's SSH dissector allow remote attackers to achieve full Remote Code Execution via controlled heap overflows.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 23 Apr 2020
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-11939, GHSA-x59q-66q3-mmf8

## What is CVE-2020-11939?

CVE-2020-11939 is a critical vulnerability in n/a, published on 23 Apr 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

In nDPI through 3.2 Stable, the SSH protocol dissector has multiple KEXINIT integer overflows that result in a controlled remote heap overflow in concat_hash_string in ssh.c. Due to the granular nature of the overflow primitive and the ability to control both the contents and layout of the nDPI library's heap memory through remote input, this vulnerability may be abused to achieve full Remote Code Execution against any network inspection stack that is linked against nDPI and uses it to perform network traffic analysis.

Weakness: CWE-787 (Out-of-bounds Write), CWE-190 (Integer Overflow or Wraparound)

## Which versions are affected by CVE-2020-11939?

It affects 1 product.


Products: Ntop Ndpi.

## How do I fix CVE-2020-11939?

Upgrade to a fixed version.

## Is CVE-2020-11939 being exploited?

There is no known exploitation of CVE-2020-11939 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2020-15474](https://insights.sbomify.com/CVE-2020-15474/): Memory corruption in n/a (critical 9.8)
- [CVE-2020-15475](https://insights.sbomify.com/CVE-2020-15475/): Use after free in n/a (critical 9.8)
- [CVE-2020-15471](https://insights.sbomify.com/CVE-2020-15471/): Memory corruption in n/a (critical 9.1)
- [CVE-2020-15473](https://insights.sbomify.com/CVE-2020-15473/): Memory corruption in n/a (critical 9.1)
- [CVE-2021-36082](https://insights.sbomify.com/CVE-2021-36082/): Memory corruption in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-11939 and fix it if it is affected.

What it is: CVE-2020-11939 is a critical vulnerability in n/a, published on 23 Apr 2020. 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-2020-11939 in the wild and no public exploit code.

Affected product: n/a. 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-2020-11939/ (Markdown: https://insights.sbomify.com/CVE-2020-11939/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-11939
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-11939
- OSV: https://osv.dev/vulnerability/CVE-2020-11939

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-11939/
Summaries are generated and may contain mistakes; the official description above is the record.