# CVE-2019-18936: Denial of service in n/a

> Attackers can cause a denial of service in applications using the UniValue library by sending input that triggers an internal state inconsistency.

- **Severity:** High 7.5 (`CVSS:3.1/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:** 21 Mar 2020
- **Updated:** 5 Aug 2024
- **Also known as:** DEBIAN-CVE-2019-18936, GHSA-wx4x-g99q-9526, UBUNTU-CVE-2019-18936

## What is CVE-2019-18936?

CVE-2019-18936 is a high-severity denial of service vulnerability in n/a, published on 21 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

UniValue::read() in UniValue before 1.0.5 allow attackers to cause a denial of service (the class internal data reaches an inconsistent state) via input data that triggers an error.

Weakness: CWE-674 (Uncontrolled Recursion)

## Which versions are affected by CVE-2019-18936?

It affects 1 product.


Products: Bloq Univalue.

## How do I fix CVE-2019-18936?

Upgrade to a fixed version.

## Is CVE-2019-18936 being exploited?

There is no known exploitation of CVE-2019-18936 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-18936 and fix it if it is affected.

What it is: CVE-2019-18936 is a high-severity denial of service vulnerability in n/a, published on 21 Mar 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-2019-18936 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-2019-18936/ (Markdown: https://insights.sbomify.com/CVE-2019-18936/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-18936
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-18936
- OSV: https://osv.dev/vulnerability/CVE-2019-18936

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From sbomify Insights: https://insights.sbomify.com/CVE-2019-18936/
Summaries are generated and may contain mistakes; the official description above is the record.