CVE-2022-21688 Out-of-bounds Read in Onionshare
An attacker can cause a denial of service in OnionShare by triggering excessive memory consumption via malicious image data in the history tab.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-21688?
CVE-2022-21688 is a high-severity denial of service vulnerability in onionshare, published on 18 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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. Affected versions of the desktop application were found to be vulnerable to denial of service via an undisclosed vulnerability in the QT image parsing. Roughly 20 bytes lead to 2GB memory consumption and this can be triggered multiple times. To be abused, this vulnerability requires rendering in the history tab, so some user interaction is required. An adversary with knowledge of the Onion service address in public mode or with authentication in private mode can perform a Denial of Service attack, which quickly results in out-of-memory for the server. This requires the desktop application with rendered history, therefore the impact is only elevated. This issue has been patched in version 2.5.
Weakness: CWE-125
Which versions are affected by CVE-2022-21688?
3 open source packages ship an affected version, including onionshare-cli. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
onionshare-cli PyPI | All versions | 2.5 |
onionshare-cli PyPI | All versions | 2.5 |
onionshare-cli PyPI | All versions | 2.5 |
Products include Onionshare Onionshare.
How do I fix CVE-2022-21688?
Upgrade onionshare-cli to 2.5 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2022-21688 being exploited?
There is no known exploitation of CVE-2022-21688 in the wild and no public exploit code.
Other vulnerabilities in onionshare
Sources
Also known as GHSA-x7wr-283h-5h2v, PYSEC-2022-39, UBUNTU-CVE-2022-21688.