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https://github.com/hakivvi/CVE-2022-29464
WSO2 RCE (CVE-2022-29464) exploit and writeup.
https://github.com/hakivvi/CVE-2022-29464
cve-2022-29464
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WSO2 RCE (CVE-2022-29464) exploit and writeup.
- Host: GitHub
- URL: https://github.com/hakivvi/CVE-2022-29464
- Owner: hakivvi
- Created: 2022-04-20T21:23:52.000Z (over 2 years ago)
- Default Branch: main
- Last Pushed: 2022-04-27T05:52:43.000Z (over 2 years ago)
- Last Synced: 2024-06-06T20:03:34.296Z (5 months ago)
- Topics: cve-2022-29464
- Language: Python
- Homepage:
- Size: 54.7 KB
- Stars: 363
- Watchers: 8
- Forks: 93
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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- awesome-hacking-lists - hakivvi/CVE-2022-29464 - WSO2 RCE (CVE-2022-29464) exploit and writeup. (Python)
README
# CVE-2022-29464
WSO2 RCE (CVE-2022-29464) exploit and writeup.
# Details
[CVE-2022-29464](https://docs.wso2.com/display/Security/Security+Advisory+WSO2-2021-1738) is critical vulnerability on WSO2 discovered by [Orange Tsai](https://twitter.com/orange_8361). the vulnerability is an unauthenticated unrestricted arbitrary file upload which allows unauthenticated attackers to gain RCE on WSO2 servers via uploading malicious JSP files.
the vulerable upload route is `/fileupload` which is handled by [`FileUploadServlet`](https://github.com/wso2/carbon-kernel/blob/4.4.x/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/FileUploadServlet.java) servlet. and it is unprotected route by IAM as we can see in the `indentity.xml` configuration file:
```xml
```
And also unprotected by the default login measure, `handleSecurity()` is the function responsible for securing the different routes served by WSO2 and provides a mechanism for performing security checks on the received HTTP requests, `handleSecurity()` will call `CarbonUILoginUtil.handleLoginPageRequest()` and based on its return value it will be decided to allow or deny access to the requested URI:
```java
public boolean handleSecurity(HttpServletRequest request, HttpServletResponse response)
throws IOException {
[snipped]
if ((val = CarbonUILoginUtil.handleLoginPageRequest(requestedURI, request, response,
authenticated, context, indexPageURL)) != CarbonUILoginUtil.CONTINUE) {
if (val == CarbonUILoginUtil.RETURN_TRUE) {
return true;
} else {
return false;
}
}
[snipped]
}
```
`CarbonUILoginUtil.handleLoginPageRequest()` returns `CarbonUILoginUtil.RETURN_TRUE` when the route is `/fileupload`:
```java
protected static int handleLoginPageRequest(String requestedURI, HttpServletRequest request,
HttpServletResponse response, boolean authenticated, String context, String indexPageURL)
throws IOException {
boolean isTryIt = requestedURI.indexOf("admin/jsp/WSRequestXSSproxy_ajaxprocessor.jsp") > -1;
boolean isFileDownload = requestedURI.endsWith("/filedownload");
if ((requestedURI.indexOf("login.jsp") > -1
|| requestedURI.indexOf("login_ajaxprocessor.jsp") > -1
|| requestedURI.indexOf("admin/layout/template.jsp") > -1
|| isFileDownload
|| requestedURI.endsWith("/fileupload")
|| requestedURI.indexOf("/fileupload/") > -1
|| requestedURI.indexOf("login_action.jsp") > -1
|| isTryIt
|| requestedURI.indexOf("tryit/JAXRSRequestXSSproxy_ajaxprocessor.jsp") > -1)
&& !requestedURI.contains(";")) {
if ((requestedURI.indexOf("login.jsp") > -1
|| requestedURI.indexOf("login_ajaxprocessor.jsp") > -1 || requestedURI
.indexOf("login_action.jsp") > -1) && authenticated) {
[snipped]
} else if ((isTryIt || isFileDownload) && !authenticated) {
[snipped]
} else if (requestedURI.indexOf("login_action.jsp") > -1 && !authenticated) {
[snipped]
} else {
if (log.isDebugEnabled()) {
log.debug("Skipping security checks for " + requestedURI);
}
return RETURN_TRUE;
}
}
return CONTINUE;
}
```
with `CarbonUILoginUtil.handleLoginPageRequest()` returning `CarbonUILoginUtil.RETURN_TRUE`, `handleSecurity()` will return `true`, the access will be then granted to `/fileupload` without authentication.
the `FileUploadServlet` servlet and upon [`init()`](https://github.com/wso2/carbon-kernel/blob/d47232dfb2b26c0ef18a74e2ef4aa503caa59697/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/FileUploadServlet.java#L71) and through a series of method calls loads eventually from the `carbon.xml` configuration file multiple upload file formats/actions along with the object which hanldes every format.
```java
public void init(ServletConfig servletConfig) throws ServletException {
this.servletConfig = servletConfig;
try {
fileUploadExecutorManager = new FileUploadExecutorManager(bundleContext, configContext, webContext);
//Registering FileUploadExecutor Manager as an OSGi service
bundleContext.registerService(FileUploadExecutorManager.class.getName(), fileUploadExecutorManager, null);
} catch (CarbonException e) {
log.error("Exception occurred while trying to initialize FileUploadServlet", e);
throw new ServletException(e);
}
}
```
the [`FileUploadExecutorManager`](https://github.com/wso2/carbon-kernel/blob/d47232dfb2b26c0ef18a74e2ef4aa503caa59697/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/fileupload/FileUploadExecutorManager.java#L67) class constructor is as follows:
```java
public FileUploadExecutorManager(BundleContext bundleContext,
ConfigurationContext configCtx,
String webContext) throws CarbonException {
this.bundleContext = bundleContext;
this.configContext = configCtx;
this.webContext = webContext;
this.loadExecutorMap();
}
```
the constructor calls the private method [`loadExecutorMap()`](https://github.com/wso2/carbon-kernel/blob/d47232dfb2b26c0ef18a74e2ef4aa503caa59697/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/fileupload/FileUploadExecutorManager.java#L131) which is where the configuration loading is done:
```java
private void loadExecutorMap() throws CarbonException {
[snipped]
try {
documentElement = XMLUtils.toOM(serverConfiguration.getDocumentElement());
} catch (Exception e) {
String msg = "Unable to read Server Configuration.";
log.error(msg);
throw new CarbonException(msg, e);
}
[snipped]
OMElement fileUploadConfigElement =
documentElement.getFirstChildWithName(
new QName(ServerConstants.CARBON_SERVER_XML_NAMESPACE, "FileUploadConfig"));
for (Iterator iterator = fileUploadConfigElement.getChildElements(); iterator.hasNext();) {
OMElement mapppingElement = (OMElement) iterator.next();
if (mapppingElement.getLocalName().equalsIgnoreCase("Mapping")) {
OMElement actionsElement =
mapppingElement.getFirstChildWithName(
new QName(ServerConstants.CARBON_SERVER_XML_NAMESPACE, "Actions"));
String confPath = System.getProperty(CarbonBaseConstants.CARBON_CONFIG_DIR_PATH);
[snipped]
```
the file upload formats configurations is within the `FileUploadConfig` namespace in the XML configuration file, this is the default configuration:
```xml
100
keystore
certificate
*
org.wso2.carbon.ui.transports.fileupload.AnyFileUploadExecutor
jarZip
org.wso2.carbon.ui.transports.fileupload.JarZipUploadExecutor
dbs
org.wso2.carbon.ui.transports.fileupload.DBSFileUploadExecutor
tools
org.wso2.carbon.ui.transports.fileupload.ToolsFileUploadExecutor
toolsAny
org.wso2.carbon.ui.transports.fileupload.ToolsAnyFileUploadExecutor
```
the `loadExecutorMap()` method creates and fills a `HashMap` of `` with the Actions and the Classes extracted from the config file. which will be later used to choose which class to use to handle properly a given format/action.
Later on when the `/fileupload` route recieves a POST request the [`doPost()`](https://github.com/wso2/carbon-kernel/blob/d47232dfb2b26c0ef18a74e2ef4aa503caa59697/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/FileUploadServlet.java#L53) method of the servlet will be called. the method just forwards the request and response object to `execute()` method of `fileUploadExecutorManager` which was intitialized on `init()`
```java
protected void doPost(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
try {
fileUploadExecutorManager.execute(request, response);
} catch (Exception e) {
String msg = "File upload failed ";
log.error(msg, e);
throw new ServletException(e);
}
}
```
the `execute()` method, splits the request url just after the `fileupload/` string, which means it extacts whatever is after the `/fileupload/` in the request URL and it assignes is it to `actionString`.
```java
public boolean execute(HttpServletRequest request,
HttpServletResponse response) throws IOException {
HttpSession session = request.getSession();
String cookie = (String) session.getAttribute(ServerConstants.ADMIN_SERVICE_COOKIE);
request.setAttribute(CarbonConstants.ADMIN_SERVICE_COOKIE, cookie);
request.setAttribute(CarbonConstants.WEB_CONTEXT, webContext);
request.setAttribute(CarbonConstants.SERVER_URL,
CarbonUIUtil.getServerURL(request.getSession().getServletContext(),
request.getSession()));
String requestURI = request.getRequestURI();
//TODO - fileupload is hardcoded
int indexToSplit = requestURI.indexOf("fileupload/") + "fileupload/".length();
String actionString = requestURI.substring(indexToSplit);
// Register execution handlers
FileUploadExecutionHandlerManager execHandlerManager =
new FileUploadExecutionHandlerManager();
CarbonXmlFileUploadExecHandler carbonXmlExecHandler =
new CarbonXmlFileUploadExecHandler(request, response, actionString);
execHandlerManager.addExecHandler(carbonXmlExecHandler);
OSGiFileUploadExecHandler osgiExecHandler =
new OSGiFileUploadExecHandler(request, response);
execHandlerManager.addExecHandler(osgiExecHandler);
AnyFileUploadExecHandler anyFileExecHandler =
new AnyFileUploadExecHandler(request, response);
execHandlerManager.addExecHandler(anyFileExecHandler);
execHandlerManager.startExec();
return true;
}
```
the `actionString` is passed to `CarbonXmlFileUploadExecHandler` class constructor along with `request` and `response`:
```java
private CarbonXmlFileUploadExecHandler(HttpServletRequest request,
HttpServletResponse response,
String actionString) {
this.request = request;
this.response = response;
this.actionString = actionString;
}
```
the constructor will save them to its properties.
after that `carbonXmlExecHandler` object along with other objects will be added to [`execHandlerManager`](https://github.com/wso2/carbon-kernel/blob/d47232dfb2b26c0ef18a74e2ef4aa503caa59697/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/fileupload/FileUploadExecutorManager.java#L298) using `addExecHandler()` method.
```java
public void addExecHandler(FileUploadExecutionHandler handler) {
if (prevHandler != null) {
prevHandler.setNext(handler);
} else {
firstHandler = handler;
}
prevHandler = handler;
}
```
then `execHandlerManager.startExec()` is called:
```java
public void startExec() throws IOException {
firstHandler.execute();
}
```
`startExec()` calls [`execute()`](https://github.com/wso2/carbon-kernel/blob/d47232dfb2b26c0ef18a74e2ef4aa503caa59697/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/fileupload/FileUploadExecutorManager.java#L430) of the first object added which is `CarbonXmlFileUploadExecHandler`:
```java
public void execute() throws IOException {
boolean foundExecutor = false;
for (String key : executorMap.keySet()) {
if (key.equals(actionString)) {
AbstractFileUploadExecutor obj = executorMap.get(key);
foundExecutor = true;
obj.executeGeneric(request, response, configContext);
break;
}
}
if (!foundExecutor) {
next();
}
}
```
[`execute()`](https://github.com/wso2/carbon-kernel/blob/d47232dfb2b26c0ef18a74e2ef4aa503caa59697/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/fileupload/FileUploadExecutorManager.java#L430) loops trough the `HashMap` of `` created earlier and finds the Action (key) which is equal to `actionString`, if found the `executeGeneric()` method of the object associated with that Action will be called.
to revise the default configuration has 7 actions which are:
* `keystore`, `certificate`, `*` handled by `org.wso2.carbon.ui.transports.fileupload.AnyFileUploadExecutor`
* `jarZip` handled by `org.wso2.carbon.ui.transports.fileupload.JarZipUploadExecutor`
* `dbs` handled by `org.wso2.carbon.ui.transports.fileupload.DBSFileUploadExecutor`
* `tools` handled by `org.wso2.carbon.ui.transports.fileupload.ToolsFileUploadExecutor`
* `toolsAny` handled by `org.wso2.carbon.ui.transports.fileupload.ToolsAnyFileUploadExecutor`
each of these objects does handle the upload differently some of them accepts specific extensions.
the first one i found vulnerable to arbitraty file write was `toolsAny` ([`ToolsAnyFileUploadExecutor`](https://github.com/wso2/carbon-kernel/blob/4.4.x/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/fileupload/ToolsAnyFileUploadExecutor.java)).
`ToolsAnyFileUploadExecutor` does not have a `executeGeneric()` method but it extends [`AbstractFileUploadExecutor`](https://github.com/wso2/carbon-kernel/blob/d47232dfb2b26c0ef18a74e2ef4aa503caa59697/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/fileupload/AbstractFileUploadExecutor.java#L61) which does have a [`executeGeneric()`](https://github.com/wso2/carbon-kernel/blob/d47232dfb2b26c0ef18a74e2ef4aa503caa59697/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/fileupload/AbstractFileUploadExecutor.java#L97) method:
```java
boolean executeGeneric(HttpServletRequest request,
HttpServletResponse response,
ConfigurationContext configurationContext) throws IOException {//,
// CarbonException {
this.configurationContext = configurationContext;
try {
parseRequest(request);
return execute(request, response);
} catch (FileUploadFailedException e) {
sendErrorRedirect(request, response, e);
} catch (FileSizeLimitExceededException e) {
sendErrorRedirect(request, response, e);
} catch (CarbonException e) {
sendErrorRedirect(request, response, e);
}
return false;
}
```
`executeGeneric()` calls first `parseRequest()` with the request object as a parameter:
```java
protected void parseRequest(HttpServletRequest request) throws FileUploadFailedException,
FileSizeLimitExceededException {
fileItemsMap.set(new HashMap>());
formFieldsMap.set(new HashMap>());
ServletRequestContext servletRequestContext = new ServletRequestContext(request);
boolean isMultipart = ServletFileUpload.isMultipartContent(servletRequestContext);
Long totalFileSize = 0L;
if (isMultipart) {
List items;
try {
items = parseRequest(servletRequestContext);
} catch (FileUploadException e) {
String msg = "File upload failed";
log.error(msg, e);
throw new FileUploadFailedException(msg, e);
}
boolean multiItems = false;
if (items.size() > 1) {
multiItems = true;
}
// Add the uploaded items to the corresponding maps.
for (Iterator iter = items.iterator(); iter.hasNext();) {
FileItem item = (FileItem) iter.next();
String fieldName = item.getFieldName().trim();
if (item.isFormField()) {
if (formFieldsMap.get().get(fieldName) == null) {
formFieldsMap.get().put(fieldName, new ArrayList());
}
try {
formFieldsMap.get().get(fieldName).add(new String(item.get(), "UTF-8"));
} catch (UnsupportedEncodingException ignore) {
}
} else {
String fileName = item.getName();
if ((fileName == null || fileName.length() == 0) && multiItems) {
continue;
}
if (fileItemsMap.get().get(fieldName) == null) {
fileItemsMap.get().put(fieldName, new ArrayList());
}
totalFileSize += item.getSize();
if (totalFileSize < totalFileUploadSizeLimit) {
fileItemsMap.get().get(fieldName).add(new FileItemData(item));
} else {
throw new FileSizeLimitExceededException(getFileSizeLimit() / 1024 / 1024);
}
}
}
}
}
```
it first assures that the POST request is a multipart POST request, and then extarcts the uploaded files, assures that the POST request contains at least on uploaded file and validates it against the maximum file size.
after returning from `parseRequest()`, `executeGeneric()` will call now the `execute()` method which is [overrode](https://github.com/wso2/carbon-kernel/blob/d47232dfb2b26c0ef18a74e2ef4aa503caa59697/core/org.wso2.carbon.ui/src/main/java/org/wso2/carbon/ui/transports/fileupload/ToolsAnyFileUploadExecutor.java#L36) by `ToolsAnyFileUploadExecutor`:
```java
@Override
public boolean execute(HttpServletRequest request,
HttpServletResponse response) throws CarbonException, IOException {
PrintWriter out = response.getWriter();
try {
Map fileResourceMap =
(Map) configurationContext
.getProperty(ServerConstants.FILE_RESOURCE_MAP);
if (fileResourceMap == null) {
fileResourceMap = new TreeBidiMap();
configurationContext.setProperty(ServerConstants.FILE_RESOURCE_MAP,
fileResourceMap);
}
List fileItems = getAllFileItems();
//String filePaths = "";
for (FileItemData fileItem : fileItems) {
String uuid = String.valueOf(
System.currentTimeMillis() + Math.random());
String serviceUploadDir =
configurationContext
.getProperty(ServerConstants.WORK_DIR) +
File.separator +
"extra" + File
.separator +
uuid + File.separator;
File dir = new File(serviceUploadDir);
if (!dir.exists()) {
dir.mkdirs();
}
File uploadedFile = new File(dir, fileItem.getFileItem().getFieldName());
try (FileOutputStream fileOutStream = new FileOutputStream(uploadedFile)) {
fileItem.getDataHandler().writeTo(fileOutStream);
fileOutStream.flush();
}
response.setContentType("text/plain; charset=utf-8");
//filePaths = filePaths + uploadedFile.getAbsolutePath() + ",";
fileResourceMap.put(uuid, uploadedFile.getAbsolutePath());
out.write(uuid);
}
//filePaths = filePaths.substring(0, filePaths.length() - 1);
//out.write(filePaths);
out.flush();
} catch (Exception e) {
log.error("File upload FAILED", e);
out.write("" +
"top.wso2.wsf.Util.alertWarning('File upload FAILED. File may be non-existent or invalid.');" +
"");
} finally {
out.close();
}
return true;
}
```
Here is where the bug lies, `execute()` method is vulnerable to a path traversal vulenerabulity as it trusts the filename given by the user in the POST request. without the path traversal escaping the tmp dir the file is actually saved to:
```
./tmp/work/extra/$uuid/$filename
```
with `uuid` being returned in the response:
the file can be found in:
Now we just need to escape the `tmp` directory and add our JSP shell to some location being served by the WSO2.
lets find the tomcat `appBase` directory:
this directory is the location of the applications that are deployed on tomcat, it contains multiple already deployed WAR applications and also thier raw WAR files:
```
./repository/deployment/server/webapps
```
one of those applications is `authenticationendpoint` (`//host/authenticationendpoint`) which handles the authentication to WSO2 and its location is:
```
./repository/deployment/server/webapps/authenticationendpoint
```
**NOTE:** we can also use the vulnerability to create our own fresh directory (context path) in the `appBase` directory and it will be auto deployed, but i will just carry one and use `authenticationendpoint`.
# PoC
* Using Burpsuite:
* Using exploiy.py:
> Usage:
> ```
> python3 exploit.py https://host:9443/ ArbitraryShellName.jsp
> ```
