Repository: projectdiscovery/nuclei

Issue:
VNC Enhancement
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### Please describe your feature request:
<!-- A clear and concise description of feature to implement -->
[ ] VNC Authentication
### Describe the use case of this feature:
<!-- A clear and concise description of the feature request's motivation and the use-cases in which it could be useful. -->

https://nmap.org/nsedoc/scripts/vnc-brute.html


Discussion:

Solution patch:
diff --git a/go.mod b/go.mod
index 60d4ef09..6d0541da 100644
--- a/go.mod
+++ b/go.mod
@@ -149,6 +149,7 @@ require (
 	github.com/alecthomas/kingpin/v2 v2.4.0 // indirect
 	github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 // indirect
 	github.com/alecthomas/units v0.0.0-20211218093645-b94a6e3cc137 // indirect
+	github.com/alexsnet/go-vnc v0.1.0 // indirect
 	github.com/andybalholm/brotli v1.1.2-0.20250424173009-453214e765f3 // indirect
 	github.com/andybalholm/cascadia v1.3.3 // indirect
 	github.com/aws/aws-sdk-go-v2/aws/protocol/eventstream v1.6.11 // indirect
diff --git a/go.sum b/go.sum
index 59725b25..8c73280a 100644
--- a/go.sum
+++ b/go.sum
@@ -378,6 +378,8 @@ github.com/alecthomas/units v0.0.0-20211218093645-b94a6e3cc137 h1:s6gZFSlWYmbqAu
 github.com/alecthomas/units v0.0.0-20211218093645-b94a6e3cc137/go.mod h1:OMCwj8VM1Kc9e19TLln2VL61YJF0x1XFtfdL4JdbSyE=
 github.com/alexbrainman/sspi v0.0.0-20231016080023-1a75b4708caa h1:LHTHcTQiSGT7VVbI0o4wBRNQIgn917usHWOd6VAffYI=
 github.com/alexbrainman/sspi v0.0.0-20231016080023-1a75b4708caa/go.mod h1:cEWa1LVoE5KvSD9ONXsZrj0z6KqySlCCNKHlLzbqAt4=
+github.com/alexsnet/go-vnc v0.1.0 h1:vBCwPNy79WEL8V/Z5A0ngEFCvTWBAjmS048lkR2rdmY=
+github.com/alexsnet/go-vnc v0.1.0/go.mod h1:bbRsg41Sh3zvrnWsw+REKJVGZd8Of2+S0V1G0ZaBhlU=
 github.com/alitto/pond v1.9.2 h1:9Qb75z/scEZVCoSU+osVmQ0I0JOeLfdTDafrbcJ8CLs=
 github.com/alitto/pond v1.9.2/go.mod h1:xQn3P/sHTYcU/1BR3i86IGIrilcrGC2LiS+E2+CJWsI=
 github.com/andybalholm/brotli v1.0.5/go.mod h1:fO7iG3H7G2nSZ7m0zPUDn85XEX2GTukHGRSepvi9Eig=
diff --git a/pkg/js/generated/go/libvnc/vnc.go b/pkg/js/generated/go/libvnc/vnc.go
index 625f3776..fa060ec1 100644
--- a/pkg/js/generated/go/libvnc/vnc.go
+++ b/pkg/js/generated/go/libvnc/vnc.go
@@ -21,6 +21,7 @@ func init() {
 
 			// Objects / Classes
 			"IsVNCResponse": gojs.GetClassConstructor[lib_vnc.IsVNCResponse](&lib_vnc.IsVNCResponse{}),
+			"VNCClient":     gojs.GetClassConstructor[lib_vnc.VNCClient](&lib_vnc.VNCClient{}),
 		},
 	).Register()
 }
diff --git a/pkg/js/generated/ts/vnc.ts b/pkg/js/generated/ts/vnc.ts
index 870151e2..f74edb89 100755
--- a/pkg/js/generated/ts/vnc.ts
+++ b/pkg/js/generated/ts/vnc.ts
@@ -33,3 +33,34 @@ export interface IsVNCResponse {
     Banner?: string,
 }
 
+/**
+ * VNCClient is a client for VNC servers.
+ * @example
+ * ```javascript
+ * const vnc = require('nuclei/vnc');
+ * const client = new vnc.VNCClient();
+ * ```
+ */
+export class VNCClient {
+    
+
+    // Constructor of VNCClient
+    constructor() {}
+    
+    /**
+    * Connect connects to VNC server using given password.
+    * If connection and authentication is successful, it returns true.
+    * If connection or authentication is unsuccessful, it returns false and error.
+    * The connection is closed after the function returns.
+    * @example
+    * ```javascript
+    * const vnc = require('nuclei/vnc');
+    * const client = new vnc.VNCClient();
+    * const connected = client.Connect('acme.com', 5900, 'password');
+    * ```
+    */
+    public Connect(host: string, port: number, password: string): boolean | null {
+        return null;
+    }
+}
+
diff --git a/pkg/js/libs/vnc/vnc.go b/pkg/js/libs/vnc/vnc.go
index bd28ad69..63c3e6a3 100644
--- a/pkg/js/libs/vnc/vnc.go
+++ b/pkg/js/libs/vnc/vnc.go
@@ -7,9 +7,11 @@ import (
 	"strconv"
 	"time"
 
+	vnclib "github.com/alexsnet/go-vnc"
 	"github.com/praetorian-inc/fingerprintx/pkg/plugins"
-	"github.com/praetorian-inc/fingerprintx/pkg/plugins/services/vnc"
+	vncplugin "github.com/praetorian-inc/fingerprintx/pkg/plugins/services/vnc"
 	"github.com/projectdiscovery/nuclei/v3/pkg/protocols/common/protocolstate"
+	stringsutil "github.com/projectdiscovery/utils/strings"
 )
 
 type (
@@ -24,8 +26,89 @@ type (
 		IsVNC  bool
 		Banner string
 	}
+
+	// VNCClient is a client for VNC servers.
+	// @example
+	// ```javascript
+	// const vnc = require('nuclei/vnc');
+	// const client = new vnc.VNCClient();
+	// const connected = client.Connect('acme.com', 5900, 'password');
+	// log(toJSON(connected));
+	// ```
+	VNCClient struct{}
 )
 
+// Connect connects to VNC server using given password.
+// If connection and authentication is successful, it returns true.
+// If connection or authentication is unsuccessful, it returns false and error.
+// The connection is closed after the function returns.
+// @example
+// ```javascript
+// const vnc = require('nuclei/vnc');
+// const client = new vnc.VNCClient();
+// const connected = client.Connect('acme.com', 5900, 'password');
+// ```
+func (c *VNCClient) Connect(ctx context.Context, host string, port int, password string) (bool, error) {
+	executionId := ctx.Value("executionId").(string)
+	return connect(executionId, host, port, password)
+}
+
+// connect attempts to authenticate with a VNC server using the given password
+func connect(executionId string, host string, port int, password string) (bool, error) {
+	if host == "" || port <= 0 {
+		return false, fmt.Errorf("invalid host or port")
+	}
+	if !protocolstate.IsHostAllowed(executionId, host) {
+		// host is not valid according to network policy
+		return false, protocolstate.ErrHostDenied.Msgf(host)
+	}
+
+	dialer := protocolstate.GetDialersWithId(executionId)
+	if dialer == nil {
+		return false, fmt.Errorf("dialers not initialized for %s", executionId)
+	}
+
+	conn, err := dialer.Fastdialer.Dial(context.TODO(), "tcp", net.JoinHostPort(host, strconv.Itoa(port)))
+	if err != nil {
+		return false, err
+	}
+	defer func() {
+		_ = conn.Close()
+	}()
+
+	// Set connection timeout
+	_ = conn.SetDeadline(time.Now().Add(10 * time.Second))
+
+	// Create VNC client config with password
+	vncConfig := vnclib.NewClientConfig(password)
+
+	// Attempt to connect and authenticate
+	c, err := vnclib.Connect(context.TODO(), conn, vncConfig)
+	if err != nil {
+		// Check for specific authentication errors
+		if isAuthError(err) {
+			return false, nil // Authentication failed, but connection succeeded
+		}
+		return false, err // Connection or other error
+	}
+	if c != nil {
+		_ = c.Close()
+	}
+
+	return true, nil
+}
+
+// isAuthError checks if the error is an authentication failure
+func isAuthError(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	// Check for common VNC authentication error messages
+	errStr := err.Error()
+	return stringsutil.ContainsAnyI(errStr, "authentication", "auth", "password", "invalid", "failed")
+}
+
 // IsVNC checks if a host is running a VNC server.
 // It returns a boolean indicating if the host is running a VNC server
 // and the banner of the VNC server.
@@ -57,7 +140,7 @@ func isVNC(executionId string, host string, port int) (IsVNCResponse, error) {
 		_ = conn.Close()
 	}()
 
-	vncPlugin := vnc.VNCPlugin{}
+	vncPlugin := vncplugin.VNCPlugin{}
 	service, err := vncPlugin.Run(conn, timeout, plugins.Target{Host: host})
 	if err != nil {
 		return resp, err



Test patch:
diff --git a/cmd/integration-test/javascript.go b/cmd/integration-test/javascript.go
index 61516abd..6e99b7f8 100644
--- a/cmd/integration-test/javascript.go
+++ b/cmd/integration-test/javascript.go
@@ -16,12 +16,14 @@ var jsTestcases = []TestCaseInfo{
 	{Path: "protocols/javascript/net-multi-step.yaml", TestCase: &networkMultiStep{}},
 	{Path: "protocols/javascript/net-https.yaml", TestCase: &javascriptNetHttps{}},
 	{Path: "protocols/javascript/oracle-auth-test.yaml", TestCase: &javascriptOracleAuthTest{}, DisableOn: func() bool { return osutils.IsWindows() || osutils.IsOSX() }},
+	{Path: "protocols/javascript/vnc-pass-brute.yaml", TestCase: &javascriptVncPassBrute{}},
 }
 
 var (
 	redisResource  *dockertest.Resource
 	sshResource    *dockertest.Resource
 	oracleResource *dockertest.Resource
+	vncResource    *dockertest.Resource
 	pool           *dockertest.Pool
 	defaultRetry   = 3
 )
@@ -110,6 +112,39 @@ func (j *javascriptOracleAuthTest) Execute(filePath string) error {
 	tempPort := oracleResource.GetPort("1521/tcp")
 	finalURL := "localhost:" + tempPort
 	defer purge(oracleResource)
+
+	errs := []error{}
+	for i := 0; i < defaultRetry; i++ {
+		results := []string{}
+		var err error
+		_ = pool.Retry(func() error {
+			//let ssh server start
+			time.Sleep(3 * time.Second)
+			results, err = testutils.RunNucleiTemplateAndGetResults(filePath, finalURL, debug)
+			return nil
+		})
+		if err != nil {
+			return err
+		}
+		if err := expectResultsCount(results, 1); err == nil {
+			return nil
+		} else {
+			errs = append(errs, err)
+		}
+	}
+	return multierr.Combine(errs...)
+}
+
+type javascriptVncPassBrute struct{}
+
+func (j *javascriptVncPassBrute) Execute(filePath string) error {
+	if vncResource == nil || pool == nil {
+		// skip test as vnc is not running
+		return nil
+	}
+	tempPort := vncResource.GetPort("5900/tcp")
+	finalURL := "localhost:" + tempPort
+	defer purge(vncResource)
 	errs := []error{}
 	for i := 0; i < defaultRetry; i++ {
 		results := []string{}
@@ -216,4 +251,22 @@ func init() {
 	if err := oracleResource.Expire(30); err != nil {
 		log.Printf("Could not expire Oracle resource: %s", err)
 	}
+
+	// setup a temporary vnc server
+	vncResource, err = pool.RunWithOptions(&dockertest.RunOptions{
+		Repository: "dorowu/ubuntu-desktop-lxde-vnc",
+		Tag:        "latest",
+		Env: []string{
+			"VNC_PASSWORD=mysecret",
+		},
+		Platform: "linux/amd64",
+	})
+	if err != nil {
+		log.Printf("Could not start resource: %s", err)
+		return
+	}
+	// by default expire after 30 sec
+	if err := vncResource.Expire(30); err != nil {
+		log.Printf("Could not expire resource: %s", err)
+	}
 }
diff --git a/integration_tests/protocols/javascript/vnc-pass-brute.yaml b/integration_tests/protocols/javascript/vnc-pass-brute.yaml
new file mode 100644
index 00000000..68cb9df6
--- /dev/null
+++ b/integration_tests/protocols/javascript/vnc-pass-brute.yaml
@@ -0,0 +1,38 @@
+id: vnc-password-test
+
+info:
+  name: VNC Password Authentication Test
+  author: pdteam
+  severity: high
+  description: |
+    Tests VNC authentication with correct and incorrect passwords.
+  metadata:
+    shodan-query: product:"vnc"
+  tags: js,network,vnc,authentication
+
+javascript:
+  - pre-condition: |
+      isPortOpen(Host,Port)
+
+    code: |
+      let vnc = require('nuclei/vnc');
+      let client = new vnc.VNCClient();
+      client.Connect(Host, Port, Password);
+
+    args:
+      Host: "{{Host}}"
+      Port: "5900"
+      Password: "{{passwords}}"
+    payloads:
+      passwords:
+        - ""
+        - root
+        - password
+        - admin
+        - mysecret
+    stop-at-first-match: true
+      
+    matchers:
+      - type: dsl
+        dsl:
+          - "success == true"