Vulny-Code-Static-Analysis/functions.py

132 lines
4.7 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
import os
import re
from indicators import *
# Replace the nth occurence of a string
# Inspired from https://stackoverflow.com/questions/35091557/replace-nth-occurrence-of-substring-in-string
def nth_replace(string, old, new, n):
if string.count(old) >= n:
left_join = old
right_join = old
groups = string.split(old)
nth_split = [left_join.join(groups[:n]), right_join.join(groups[n:])]
return new.join(nth_split)
return string.replace(old, new)
# Display the found vulnerability with basic informations like the line
def display(path,payload,vulnerability,line,declaration_text,declaration_line, colored, occurence):
# Potential vulnerability found : SQL Injection
header = "\033[1mPotential vulnerability found : \033[92m{}\033[0m".format(payload[1])
# Line 25 in test/sqli.php
line = "\033[92m{}\033[0m in {}".format(line,path)
# Code : include($_GET['patisserie'])
vuln = nth_replace("".join(vulnerability), colored, "\033[93m"+colored+"\033[0m", occurence)
vuln = "{}({})".format(payload[0], vuln)
# Final Display
rows, columns = os.popen('stty size', 'r').read().split()
print "-" * (int(columns)-1)
print "Name " + "\t"+header
print "-" * (int(columns)-1)
print "\033[1mLine \033[0m " + "\t"+line
print "\033[1mCode \033[0m " + "\t"+vuln
# Declared at line 1 : $dest = $_GET['who'];
declared = ""
if not "$_" in colored:
if declaration_text != "":
declared = "Line n°\033[0;92m"+declaration_line+"\033[0m : "+ declaration_text
else:
declared = "Undeclared \033[0m"+ declaration_text+" in the file"
print "\033[1mDeclaration \033[0m " + "\t"+declared
# Small delimiter
print ""
# Find the line where the vulnerability is located
def find_line_vuln(path,payload,vulnerability,content):
content = content.split('\n')
for i in range(len(content)):
if payload[0]+'('+vulnerability[0]+vulnerability[1]+vulnerability[2]+')' in content[i]:
return str(i-1)
return "-1"
# Find the line where the entry point is declared
# TODO: should be an array of the declaration and modifications
def find_line_declaration(declaration, content):
content = content.split('\n')
for i in range(len(content)):
if declaration in content[i]:
return str(i)
return "-1"
# Format the source code in order to improve the detection
def clean_source_and_format(content):
# Clean up - replace tab by space
content = content.replace(" "," ")
# Quickfix to detect both echo("something") and echo "something"
content = content.replace("echo ","echo(")
content = content.replace(";",");")
return content
# Check the line to detect an eventual protection
def check_protection(payload, match):
for protection in payload:
if protection in "".join(match):
return True
return False
# Check exception - When it's a function($SOMETHING) Match declaration $SOMETHING = ...
def check_exception(match):
exceptions = ["_GET","_REQUEST","_POST","_COOKIES","_FILES"]
is_exception = False
for exception in exceptions:
if exception in match:
return True
return False
# Check declaration
def check_declaration(content, vuln, path):
# Follow and parse include, then add it's content
regex_declaration = re.compile("(include.*?|require.*?)\([\"\'](.*?)[\"\']\)")
includes = regex_declaration.findall(content)
# Path is the path of the current scanned file, we can use it to compute the relative include
for include in includes:
relative_include = os.path.dirname(path)+"/"
path_include = relative_include + include[1]
with open(path_include, 'r') as f:
content = f.read() + content
# Extract declaration - for ($something as $somethingelse)
regex_declaration2 = re.compile("\$(.*?)([\t ]*)as(?!=)([\t ]*)\$"+vuln[1:])
declaration2 = regex_declaration2.findall(content)
if len(declaration2) > 0:
return check_declaration(content, "$"+declaration2[0][0], path)
# Extract declaration - $something = $_GET['something']
regex_declaration = re.compile("\$"+vuln[1:]+"([\t ]*)=(?!=)(.*)")
declaration = regex_declaration.findall(content)
if len(declaration)>0:
# Check constant then return True if constant because it's false positive
declaration_text = "$"+vuln[1:] +declaration[0][0]+"="+declaration[0][1]
line_declaration = find_line_declaration(declaration_text, content)
regex_constant = re.compile("\$"+vuln[1:]+"([\t ]*)=[\t ]*?([\"\'(]*?[a-zA-Z0-9{}_\(\)@\.,!: ]*?[\"\')]*?);")
false_positive = regex_constant.match(declaration_text)
if false_positive:
return (True, "","")
return (False, declaration_text,line_declaration)
return (False, "","")