Denial of Service in Onionshare

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2022-21689: 1.35% estimated exploitation activity in the next 30 days; percentile 71.48 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Between September 26, 2021 and October 8, 2021, Radically Open Security conducted a penetration test of OnionShare 2.4, funded by the Open Technology Fund's Red Team lab. - Vulnerability ID: OTF-012 - Vulnerability type: Denial of Service - Threat level: Moderate Description: 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. Technical description: The following script uses GNU parallel and curl with around 6000 requests in parallel to send 10000 requests. A change in the ulimit -n configuration is required for it to work. This is sufficient to block file upload on a (public) receive instance. Attack duration was around 80 seconds. Cases where over 99 requests were sent per second: Cases where files were successfully written to disk: This means that during the attack time 1601 requests of 10000 were dropped. We tried to upload multiple files in the web interface during the attack and…

Published by the source

21 Jan 2022, 23:20 UTC

Last modified by the source

8 Oct 2024, 13:00 UTC

Source last checked

26 Oct 2026, 13:21 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-jh82-c5jw-pxpc

2. Revision 2 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-jh82-c5jw-pxpc

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# Patch Next advisory brief: CVE-2022-21689

Advisory: Denial of Service in Onionshare
IDs: CVE-2022-21689, GHSA-jh82-c5jw-pxpc
Record: https://patchnext.com/advisories/cve-2022-21689 (revision 3, source checked 26 Oct 2026, 13:21 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: onionshare-cli 2.5. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI onionshare-cli: affected < 2.5; fixed in 2.5

## Suggested inspection (read-only)
- `python -m pip show onionshare-cli`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on onionshare-cli.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-jh82-c5jw-pxpc (OSV record GHSA-jh82-c5jw-pxpc lists affected ranges: PyPI onionshare-cli >=0 <2.5 (fixed))
- Verified: https://github.com/advisories/GHSA-jh82-c5jw-pxpc (GitHub-reviewed advisory GHSA-jh82-c5jw-pxpc lists affected ranges: PyPI onionshare-cli >=0 <2.5)

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