# CVE-2020-36619: multimon-ng demod_flex.c add_ch format string

> A format string vulnerability in multimon-ng allows attackers to execute arbitrary code or cause denial of service via crafted input.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 19 Dec 2022
- **Updated:** 15 Apr 2025
- **Also known as:** DEBIAN-CVE-2020-36619, GHSA-7838-j28v-c2rp, UBUNTU-CVE-2020-36619, openSUSE-SU-2022:10253-1, openSUSE-SU-2023:0004-1

## What is CVE-2020-36619?

CVE-2020-36619 is a medium-severity vulnerability in unspecified multimon-ng, published on 19 Dec 2022. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was found in multimon-ng. It has been rated as critical. This issue affects the function add_ch of the file demod_flex.c. The manipulation of the argument ch leads to format string. Upgrading to version 1.2.0 is able to address this issue. The name of the patch is e5a51c508ef952e81a6da25b43034dd1ed023c07. It is recommended to upgrade the affected component. The identifier VDB-216269 was assigned to this vulnerability.

Weakness: CWE-134 (Use of Externally-Controlled Format String), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2020-36619?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `multimon-ng` | SUSE:Package Hub 15 SP3 | All versions | 1.2.0-bp153.2.3.1 |
| `multimon-ng` | SUSE:Package Hub 15 SP4 | All versions | 1.2.0-bp154.2.3.1 |
| `multimon-ng` | openSUSE:Leap 15.3 | All versions | 1.2.0-bp153.2.3.1 |
| `multimon-ng` | openSUSE:Leap 15.4 | All versions | 1.2.0-bp154.2.3.1 |

Products: Multimon-Ng Project Multimon-Ng.

## How do I fix CVE-2020-36619?

Upgrade to a fixed version.

## Is CVE-2020-36619 being exploited?

There is no known exploitation of CVE-2020-36619 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-36619 and fix it if it is affected.

What it is: CVE-2020-36619 is a medium-severity vulnerability in unspecified multimon-ng, published on 19 Dec 2022. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-36619 in the wild and no public exploit code.

Affected product: unspecified multimon-ng. 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-2020-36619/ (Markdown: https://insights.sbomify.com/CVE-2020-36619/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-36619
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-36619
- OSV: https://osv.dev/vulnerability/CVE-2020-36619

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-36619/
Summaries are generated and may contain mistakes; the official description above is the record.