CVE-2022-21689: Denial of Service in Onionshare
Summary
CVE-2022-21689: Denial of Service in Onionshare. 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 allows users to securely and anonymously share files over the Tor network. It provides a simple interface for users to create a temporary website on their own computer and share files with others. Onionshare is written in Python and is available on PyPI.
Vulnerability Detail
The vulnerability identified as CVE-2022-21689 is a Denial of Service (DoS) issue in Onionshare version 2.4. It was discovered during a penetration test conducted by Radically Open Security. The vulnerability allows an attacker to block file uploads for other users in the receive mode of Onionshare. By sending a large number of requests in parallel, the attacker can trigger a limitation that blocks other uploads in the same second. This limitation can be bypassed by making changes to the 'ulimit -n' configuration. The impact of this vulnerability is moderate, as it can disrupt the file sharing functionality of Onionshare.
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 provided for this vulnerability. Users are advised to update to the latest patched version of Onionshare once it becomes available.
Conclusion
The vulnerability identified as CVE-2022-21689 in Onionshare version 2.4 allows an attacker to block file uploads for other users in the receive mode. This can disrupt the file sharing functionality of Onionshare. To mitigate this vulnerability, it is recommended to update to the latest patched version of Onionshare (version 2.5 or higher) once it becomes available. For further support on vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for onionshare-cli →
FAQ
The vulnerability allows an attacker to block file uploads for other users in the receive mode of Onionshare. This can disrupt the file sharing functionality of Onionshare.
The attacker can exploit the vulnerability by sending a large number of requests in parallel, triggering the limitation on concurrent uploads in Onionshare.
No, there is no way to block this attack in public mode due to the anonymity properties of the Tor network.
The recommended solution is for the developers of Onionshare to remove the limitation on concurrent uploads or derive the directory name from milliseconds.
There are no known instances of this vulnerability being exploited in the wild.
References
Related vulnerabilities
Recent vulnerabilities recorded for onionshare-cli.
