Summary
Improper Access Control in Onionshare
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. This is an issue from that penetration test.
- Vulnerability ID: OTF-009
- Vulnerability type: Improper Access Control
- Threat level: Low
Description:
Authenticated users (or unauthenticated in public mode) can send messages without being visible in the list of chat participants.
Technical description:
Prerequisites:
- Existing chatroom
- Access to the chatroom (Public or known Private Key)
- Either a modified frontend client or manual requests from burp/curl
If a user opens the chatroom without emitting the join message he will not be present in session.users[x] list. Therefore there is no listing in the frontend and no chat participant knows another party joined the chat. It is still possible to send messages in the chatroom.
If a user decides to abuse OTF-003 (page 22) he can impersonate messages from existing users; others would not be able to distinguish original and faked messages. This is also a prerequisite for OTF-004 (page 19).
Impact
An adversary with access to the chat environment can send messages to the chat without being visible in the list of chat participants.
The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.
CVE-2022-21695 has a CVSS score of 4.3 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.5); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
- Allow chat access only after emission of the join event.
- Implement proper session handling.
Frequently Asked Questions
- What is CVE-2022-21695? CVE-2022-21695 is a medium-severity improper authentication vulnerability in onionshare-cli (pip), affecting versions >= 2.3, < 2.5. It is fixed in 2.5. The application does not adequately verify the identity of a user, device, or process before granting access.
- How severe is CVE-2022-21695? CVE-2022-21695 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of onionshare-cli are affected by CVE-2022-21695? onionshare-cli (pip) versions >= 2.3, < 2.5 is affected.
- Is there a fix for CVE-2022-21695? Yes. CVE-2022-21695 is fixed in 2.5. Upgrade to this version or later.
- Is CVE-2022-21695 exploitable, and should I be worried? Whether CVE-2022-21695 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2022-21695 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2022-21695? Upgrade
onionshare-clito 2.5 or later.