CVE-2022-21689: OnionShare receive mode allows blocking file uploads
Summary
CVE-2022-21689: OnionShare is an open source tool that lets you securely and anonymously share files, host websites, and chat with friends using the Tor network. Affects onionshare-cli versions < 2.5. Fixed in 2.5. How to fix ↓
Also tracked for
- onionshare · Debian:11
The same CVE-2022-21689 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
OnionShare is an open source tool that leverages the Tor network to enable secure and anonymous file sharing, website hosting, and chat functionalities. It provides users with the ability to share files and communicate privately while benefiting from the anonymity properties of the Tor network.
Vulnerability Detail
In affected versions of OnionShare, the receive mode has a limitation that restricts concurrent uploads to 100 per second. If a simple script is executed, it can trigger this limitation and block other uploads within the same second. This vulnerability allows an adversary with access to the receive mode to disrupt file uploads for other users. Due to the anonymity properties of the Tor network, there is no way to mitigate this attack in public mode.
How To Fix
Latest published version: 2.7.0 as of 22 Oct 2026
pip install --upgrade "onionshare-cli==2.7.0"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
2.5
This is the first release that contains the fix.
pip install --upgrade "onionshare-cli==2.5"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
There is no specific workaround available for this vulnerability. Users are advised to upgrade to the latest version of OnionShare to mitigate the issue.
Conclusion
In summary, OnionShare's receive mode in affected versions has a vulnerability that allows an adversary to block file uploads for other users. To mitigate this issue, users should upgrade to OnionShare version 2.5 or later. For further support on vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for onionshare-cli →
FAQ
OnionShare is an open source tool that enables secure and anonymous file sharing, website hosting, and chat functionalities using the Tor network.
This vulnerability allows an adversary with access to the receive mode to block file uploads for other users, potentially disrupting their file sharing activities.
No, due to the anonymity properties of the Tor network, there is no way to block this attack in public mode.
To fix this vulnerability, users should upgrade to OnionShare version 2.5 or later.
No, there is no specific workaround available for this vulnerability. Upgrading to the latest version of OnionShare is the recommended solution.
References
Related vulnerabilities
Recent vulnerabilities recorded for onionshare-cli.
