SaTC

Chinese Version.

A prototype of Shared-keywords aware Taint Checking(SaTC), a static analysis method that tracks user input between front-end and back-end for vulnerability discovery effectively and efficiently.

Overview of SaTC

Research paper

We present our approach in the following research paper accepted at the 30th USENIX Security Symposium:

Sharing More and Checking Less: Leveraging Common Input Keywords to Detect Bugs in Embedded Systems [PDF]

Running Environment

We provide a usable Docker environment and a Dockerfile that can be used to build Docker images.

Use the compiled docker environment directly

```shell script

Get image from Docker hub

docker pull smile0304/satc

Run SaTC (Need to add mapping directory by yourself)

docker run -v : -it smile0304/satc

### Or build it by dockerfile

```shell script
# Cd SaTC code directory
cd SaTC

# Use Dockerfile to build docker image
docker build . -t satc

# Run SaTC (Need to add mapping directory by yourself)
docker run -v <mapping>:<mapping> -it satc

Instructions for running this tool

Usage: satc.py [-h] -d /root/path/_ac18.extracted -o /root/output
               [--ghidra_script {ref2sink_cmdi,ref2sink_bof,share2sink,ref2share,all}]
               [--save_ghidra_project] --taint_check
               [-b /var/ac18/bin/httpd | -l 3]

Arguments:
  -h, --help            Show help in details
  -d /root/path/_ac18.extracted, --directory /root/path/_ac18.extracted
                        File system uncompressed from firmware
  -o /root/output, --output /root/output
                        Directory result saved
  --ghidra_script {ref2sink_cmdi,ref2sink_bof,share2sink,ref2share,all}
                        (Option) Specify the Ghidra script to be used. If you use the `all` command, the three scripts `ref2sink_cmdi`,`ref2sink_bof` and `ref2share` will be run at the same time
  --ref2share_result /root/path/ref2share_result 
                        (Option) When running the `share2sink` Ghidra script, you need to use this parameter to specify the output result of the `ref2share` script
  --save_ghidra_project (Option) Save the ghidra project generated during analysis
  --taint_check         (Option) Use taint analysis engine for analysis
  -b /var/ac18/bin/httpd, --bin /var/ac18/bin/httpd  OR `-b httpd` , `--bin httpd`    
                        (Option) Used to specify the program to be analyzed, if not specified, SaTC will leverage the built-in algorithm to match targeted bin
  -l num, --len num     (Option) To set the top N programs to be defined as the border bins in our matching results[Default value is 3]

Ghidra script

• ref2sink_cmdi: The script to discover the paths of the command injection type sink function from the reference of the given shared-keywords.
• ref2sink_bof : The script to discover the paths of the buffer overflow type sink function from the reference of the given shared-keywords.
• ref2share : This script to find parameters in shared data handling functions, such as nvram_set, setenv or other similar functions. Need to be used in conjunction with share2sink.
• share2sink : This script is corresponding to ref2share, such as nvram_get, getenv or other functions. Need to be used in conjunction with ref2share, and the input of this script is the output from the ref2share script.

Output

Directory structure：

|-- ghidra_extract_result
|   |-- httpd
|       |-- httpd
|       |-- httpd_ref2sink_bof.result
|       |-- httpd_ref2sink_cmdi.result
|       |-- httpd_ref2sink_cmdi.result-alter2
|-- keyword_extract_result
|   |-- detail
|   |   |-- API_detail.result
|   |   |-- API_remove_detail.result
|   |   |-- api_split.result
|   |   |-- Clustering_result_v2.result
|   |   |-- File_detail.result
|   |   |-- from_bin_add_para.result
|   |   |-- Not_Analysise_JS_File.result
|   |   |-- Prar_detail.result
|   |   |-- Prar_remove_detail.result
|   |-- info.txt
|   |-- simple
|       |-- API_simple.result
|       |-- Prar_simple.result
|-- result-httpd-ref2sink_cmdi-ctW8.txt

Need to follow such important directories:

• keyword_extract_result/detail/Clustering_result_v2.result : The match of front-end keywords in bin. Input for the Input Entry Recognition module
• ghidra_extract_result/{bin}/* : Analysis result of ghidra script. Input for Input Sensitive Taint Analysise module
• result-{bin}-{ghidra_script}-{random}.txt: taint analysis result

Other directories:

|-- ghidra_extract_result # ghidra looks for the analysis results of the function call path, enabling the `--ghidra_script` option will output the directory
|   |-- httpd # Each bin analyzed will generate a folder with the same name
|       |-- httpd # Bin being analyzed
|       |-- httpd_ref2sink_bof.result # Locate BoF sink function path
|       |-- httpd_ref2sink_cmdi.result # Locate CmdI sink function path
|-- keyword_extract_result  # Keyword extraction results
|   |-- detail  # Front-end keyword extraction results (detailed analysis results)
|   |   |-- API_detail.result # Detailed results of the extracted API
|   |   |-- API_remove_detail.result # API information filtered out
|   |   |-- api_split.result  # Matching API results
|   |   |-- Clustering_result_v2.result # Detailed matching results 
|   |   |-- File_detail.result  # Keywords extracted from each file
|   |   |-- from_bin_add_para.result # Share-keywords generated during binary matching
|   |   |-- Not_Analysise_JS_File.result #Igored JS files by common lib matching
|   |   |-- Prar_detail.result # Detailed results of extracted Prarmeters
|   |   |-- Prar_remove_detail.result # Detailed results of filtered Prarmeters
|   |-- info.txt  # Record processing time and other information
|-- result-httpd-ref2sink_cmdi-ctW8.txt # a typical result file that enable `--taint-check` and `--ghidra_script` options

Our dataset

You should download dataset from SaTC_dateset.zip.

Case Study

1.To discover command injection and buffer overflow bugs in D-Link 878 ```shell script python satc.py -d /home/satc/dlink_878 -o /home/satc/res --ghidra_script=ref2sink_cmdi --ghidra_script=ref2sink_bof --taint_check

2.To discover command injection bugs in specific target `prog.cgi` of D-Link 878 
```shell script
python satc.py -d /home/satc/dlink_878 -o /home/satc/res --ghidra_script=ref2sink_cmdi -b prog.cgi --taint_check

3.To discover command injection bugs in multi-bin of D-Link 878, setting input data in prog.cgi and sink functions in rc ```shell script python satc.py -d /home/satc/dlink_878 -o /home/satc/res --ghidra_script=ref2share -b prog.cgi

python satc.py -d /home/satc/dlink_878 -o /home/satc/res --ghidra_script=share2sink --ref2share_result=/home/satc/res/ghidra_extract_result/prog.cgi/prog.cgi_ref2share.result -b rc --taint_check ```