![wemo pc application wemo pc application](https://www.homeandsmart.de/var/site/storage/images/_aliases/inline_image/8/1/6/5/115618-1-ger-DE/wemo-app-macht-das-zuhause-zum-smarte-home.jpg)
Then the “wget” command will initiate a download from my web server, located at IP address “172.16.127.31.” The “-q” will force wget to only print what it receives, and the “-O -“ tells wget to print to STDOUT instead of a file. The “-f” as indicated before will cause the wrapper script to execute the “||” command. I decided to do this by downloading a file from a webserver I control and executing it in Ash to bypass file path sanitization characters.įigure 5: Commands allowing for execution of filtered characters. I needed to find a way to execute commands that had “/” characters in them. I found it in root’s home directory.īeing able to write arbitrary files and execute commands without the “/” character is still somewhat limiting, as most file paths and web URLs will need forward slashes.
#Wemo pc application serial#
Since I still had serial access (I explain in detail in my previous blog how I achieved this) I was able to log in to the coffee maker and find where the “test” file was located. With the wrapper script returning a failing return code, the “||” (or) statement is initiated, which executes “touch test” and creates an empty file named “test”. The “-f” is not a parsed argument, meaning it will take the “Bad option” case, causing the “rtng_run_rule” wrapper script to return “-1”. Next, I looked at the how the wrapper script is handling command line arguments as shown below.Īt this point I created a new rule: “-f|| touch test”. I noticed that I could send the double pipe “||” character but the “rtng_run_rule” wrapper script would never return a failing return code.
![wemo pc application wemo pc application](https://freesoftforpc.com/wp-content/uploads/2021/05/Download-Wemo-App-Using-Bluestacks.png)
The “rtng_run_rule” file is a shell script that directly calls a Lua script named “rtng_run_a”. I needed to find a way to terminate the “rtng_run_rule” and add my own commands to the crontab file by modifying the “id” field.
#Wemo pc application code#
Having the ability to write arbitrary code directly into the root’s crontab is enticing, so I began looking into it again. Finding an even more simple vulnerabilityĪ few months after disclosing to Belkin, I revisited the steps to achieve this template abuse feature, in preparation for a public disclosure blog.
![wemo pc application wemo pc application](https://images.anandtech.com/galleries/3576/int-01_thumb.png)
The following is a list of characters sanitized or filtered on input.Īt this point I moved on and ended up finding the template vulnerability as laid out in the previous blog. I also noticed that a lot of characters that could be useful for command injection were being filtered. The user provides both the command to execute as well as timing details down to the minute, as shown in Figure 3.ĭuring the initial research, I started to fuzz the rule id field however, because every rule name that I placed in the malicious schedule was always prepended by the “/sbin/rtng_run_rule”, I could not get anything abnormal to happen. The crontab entry uses the rule’s “id” field to make sure the correct rule is executed at the desired time.Ĭrontab allows for basic scheduling features from the OS level. When the user schedules a brew, an individual rule is added to the Mr. During that research I noticed that many of the other fields could be impactful but did not investigate them as thoroughly as the template field. I also needed to modify the template itself, sent from the WeMo App directly to the coffee maker. The first vulnerability modified the “template” section of the brew schedule rule file, which a is unique file that is sent when the user schedules a brew in advance. As it turns out, my intuition was accurate the second vulnerability I found was much simpler and still allowed me to gain root access to the target. It was during the writing of that blog that I was finally able to circle back to it. While researching the device, there was always one attack vector that I had wanted to revisit. Please refer to the earlier blog to catch up with the processes and techniques I used to investigate and ultimately compromise this smart coffee maker. McAfee Advanced Threat Research recently released a blog detailing a vulnerability in the Mr.