Cisco IOS XE 植入物扫描器

2023 年 10 月 23 日，由于所有植入物不再响应 /webui/logoutconfirm.html 的请求，Fox-IT 开发了一种新方法来判断系统是否已被入侵。具体来说，攻击者的植入物不再以重定向到登录页面的方式响应请求，而是加入了逻辑：如果请求的 URI 包含 %，则返回 404。因此，该扫描器现在会发送类似 /Fadf%25 的 HTTP GET 请求。带有植入物的系统将返回以下响应内容：

<html>
<head><title>404 Not Found</title></head>
<body bgcolor="white">
<center><h1>404 Not Found</h1></center>
<hr><center>nginx</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->

用法与之前相同（更多用法信息请参见“旧文档”部分），但我们已经无法再恢复 implant-id。

编译

你可以使用 makefile 来构建 docker 容器：

make docker

或者，如果你已经准备好 Go 构建环境，直接使用 make 即可：

albinolobster@mournland:~/cisco-ios-xe-implant-scanner$ make
gofmt -d -w implant-scanner.go 
golangci-lint run --fix implant-scanner.go
GOOS=linux GOARCH=arm64 go build -o build/implant-scanner_linux-arm64 implant-scanner.go

已植入主机的示例输出

./build/implant-scanner -a -v -c -rhost 10.9.49.180
time=2023-10-23T14:33:07.581-04:00 level=STATUS msg="Starting target" index=0 host=10.9.49.180 port=80 ssl=false "ssl auto"=true
time=2023-10-23T14:33:08.782-04:00 level=STATUS msg="Validating IOS XE target" host=10.9.49.180 port=80
time=2023-10-23T14:33:10.115-04:00 level=SUCCESS msg="Target validation succeeded!" host=10.9.49.180 port=80
time=2023-10-23T14:33:10.115-04:00 level=STATUS msg="Running a version check on the remote target" host=10.9.49.180 port=80
time=2023-10-23T14:33:10.624-04:00 level=SUCCESS msg="The target appears to be a vulnerable version!" host=10.9.49.180 port=80

未植入主机的示例输出

./build/implant-scanner -a -v -c -rhost 10.9.49.124
time=2023-10-23T14:34:31.207-04:00 level=STATUS msg="Starting target" index=0 host=10.9.49.124 port=80 ssl=false "ssl auto"=true
time=2023-10-23T14:34:31.340-04:00 level=STATUS msg="Validating IOS XE target" host=10.9.49.124 port=80
time=2023-10-23T14:34:31.363-04:00 level=SUCCESS msg="Target validation succeeded!" host=10.9.49.124 port=80
time=2023-10-23T14:34:31.363-04:00 level=STATUS msg="Running a version check on the remote target" host=10.9.49.124 port=80
time=2023-10-23T14:34:31.378-04:00 level=ERROR msg="The target appears to be a patched version." host=10.9.49.124 port=80

旧文档

按照 Cisco PSIRT 和 Cisco Talos 的描述扫描 IOS XE 植入物。该扫描器会向 /webui/logoutconfirm.html?logon_hash=1 发送 HTTP POST 请求，并在响应中查找 18 字节的十六进制字符串。当发现植入物时，扫描器输出将包含如下一行：

time=2023-10-17T06:09:02.967-04:00 level=SUCCESS msg=Found implant-id=1a80b7389ccd0a5dab rhost=192.168.1.1 rport=80 ssl=false

当未发现植入物时，扫描器会输出类似以下内容：

{"time":"2023-10-17T06:13:48.241233896-04:00","level":"ERROR","msg":"The target appears to be a patched version.","host":"192.168.1.1","port":80}

请注意，这并不表示目标已打补丁，仅表示未发现植入物。这只是 go-exploit 版本扫描器的通用输出。由于该工具基于 go-exploit 构建，它支持多种扫描功能。示例用法如下：

扫描单台主机

$ ./build/implant-scanner -rhost 192.168.1.1 -rport 80 -proxy socks5://127.0.0.1:9050 -a -v -c
time=2023-10-17T06:08:59.586-04:00 level=STATUS msg="Starting target" index=0 host=192.168.1.1port=80 ssl=false "ssl auto"=true
time=2023-10-17T06:09:00.882-04:00 level=STATUS msg="Validating IOS XE target" host=192.168.1.1port=80
time=2023-10-17T06:09:02.237-04:00 level=SUCCESS msg="Target validation succeeded!" host=192.168.1.1port=80
time=2023-10-17T06:09:02.237-04:00 level=STATUS msg="Running a version check on the remote target" host=192.168.1.1port=80
time=2023-10-17T06:09:02.967-04:00 level=SUCCESS msg=Found implant-id=1a80b7389ccd0a5dab rhost=192.168.1.1rport=80 ssl=false
time=2023-10-17T06:09:02.967-04:00 level=SUCCESS msg="The target appears to be a vulnerable version!" host=192.168.1.1port=80

通过代理扫描单台主机

$ ./build/implant-scanner -rhost 192.168.1.1-rport 80 -proxy socks5://127.0.0.1:9050 -a -v -c
time=2023-10-17T06:08:59.586-04:00 level=STATUS msg="Starting target" index=0 host=192.168.1.1port=80 ssl=false "ssl auto"=true
time=2023-10-17T06:09:00.882-04:00 level=STATUS msg="Validating IOS XE target" host=192.168.1.1port=80
time=2023-10-17T06:09:02.237-04:00 level=SUCCESS msg="Target validation succeeded!" host=192.168.1.1port=80
time=2023-10-17T06:09:02.237-04:00 level=STATUS msg="Running a version check on the remote target" host=192.168.1.1port=80
time=2023-10-17T06:09:02.967-04:00 level=SUCCESS msg=Found implant-id=1a80b7389ccd0a5dab rhost=192.168.1.1rport=80 ssl=false
time=2023-10-17T06:09:02.967-04:00 level=SUCCESS msg="The target appears to be a vulnerable version!" host=192.168.1.1port=80

扫描主机文件并将 JSON 记录到文件

有关 -rhosts-file 格式的更多信息，请参阅 go-exploit 文档。

$ ./build/implant-scanner -rhosts-file targets -log-json -log-file ./logs/output.json -v -c
$ tail logs/output.json
{"time":"2023-10-17T06:16:07.24555914-04:00","level":"STATUS","msg":"Validating IOS XE Implant target","host":"192.168.1.1","port":443}
{"time":"2023-10-17T06:16:10.363281285-04:00","level":"SUCCESS","msg":"Target validation succeeded!","host":"192.168.1.1","port":443}
{"time":"2023-10-17T06:16:10.363345035-04:00","level":"STATUS","msg":"Running a version check on the remote target","host":"192.168.1.1","port":443}