OnionshareApplication

CVE-2022-21689

HIGH · 7.5 CVSS v3.1 Published 2022-01-18
Fix available
A fix is available. Upgrade to 2.5 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

OnionShare receive mode has a rate limit of 100 concurrent uploads per second. An attacker with access to receive mode can flood the system with 100 requests per second using a simple script, blocking legitimate file uploads. This is a denial-of-service vulnerability exploiting the application's concurrency throttling mechanism.

MitigationUsers should update to the patched version of OnionShare. In public mode, the Tor anonymity properties make this attack difficult to mitigate externally; the fix must be implemented in the application itself.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
OnionshareApplication
Affected:< 2.5

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check OnionShare version
    Open OnionShare and navigate to the application menu, or run 'onionshare --version' from command line if available
    Affected if The installed version is below 2.5 (e.g., 2.4, 2.3, etc.)
  2. Identify if receive mode is in use
    Open OnionShare and verify whether the receive mode feature is enabled or can be activated - look for the 'Receive Files' option in the application interface
    Affected if Receive mode is enabled or can be enabled on the current installation
  3. Confirm public mode configuration
    Check OnionShare settings to determine if the instance is configured in public mode (allowing anonymous connections without requiring a private key)
    Affected if Public mode is enabled, as this makes the attack more impactful by allowing anonymous request flooding
  4. Verify application is exposed to network
    Confirm OnionShare is running and reachable over the network - check if the receive mode service is actively listening for incoming connections
    Affected if OnionShare receive mode is actively running and accepting connections

A user is affected if they are running OnionShare version below 2.5 with receive mode enabled and accessible, allowing an attacker to flood with 100 requests per second and block legitimate uploads.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.5 or later
Fixed in 2.5
Interim mitigation

Users should update to the patched version of OnionShare. In public mode, the Tor anonymity properties make this attack difficult to mitigate externally; the fix must be implemented in the application itself.

Recommended fix High confidence

2.5

  1. 1. Back up any current OnionShare configuration and data if needed
  2. 2. Uninstall the current version of OnionShare
  3. 3. Download OnionShare version 2.5 or later from the official source (onionshare.org)
  4. 4. Install the new version following the standard installation process for your operating system
  5. 5. Verify the installed version is 2.5 or later by checking the application or running 'onionshare --version'

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Onionshare Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,800
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,480.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-21689 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data