CVE-2022-21671 is a high-severity (CVSS 8.1) Information Exposure vulnerability in @replit/crosis. A fix is available for @replit/crosis — see the affected versions and patch details below.
Potential exposure of Replit tokens to an Unauthorized Actor in @replit/crosis
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2022-21671.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2022-21671 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
@replit/crosisnpmDescription
Impact
When using this library as a way to programmatically communicate with Replit in a standalone fashion, if there are multiple failed attempts to contact Replit through a WebSocket, the library will attempt to communicate using a fallback poll-based proxy. The URL of the proxy has changed, so any communication done to the previous URL could potentially reach a server that is outside of Replit's control and the token used to connect to the Repl could be obtained by an attacker, leading to full compromise of that Repl (not of the account).
Patches
This was patched in 7.3.1, by updating the address of the fallback WebSocket polling proxy to the new one.
Workarounds
Specify the new address for the polling host (gp-v2.replit.com) in the ConnectArgs:
const connectOptions: ConnectArgs = {
// ...
pollingHost: 'gp-v2.replit.com',
};
client.connect(connectOptions);
For more information
Thanks to https://hackerone.com/orlserg for disclosing this.
If you have any questions or comments about this advisory:
- Open an issue in replit/crosis
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @replit/crosis | all versions | 7.3.1npm install @replit/crosis@7.3.1 |
Affected Products
crosisreplitDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @replit/crosis, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @replit/crosis to 7.3.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-21671 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
Frequently Asked Questions
Is CVE-2022-21671 in your dependencies?
Find it across npm, including transitive dependencies.