From 35a25bc1aa077c633b6150f60a9b7d92e3f9c7c4 Mon Sep 17 00:00:00 2001 From: Hardik Shah Date: Thu, 13 Jul 2023 12:51:54 +0530 Subject: [PATCH] cleanup --- linux/imgRead.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 linux/imgRead.c diff --git a/linux/imgRead.c b/linux/imgRead.c new file mode 100644 index 0000000..fbfaef3 --- /dev/null +++ b/linux/imgRead.c @@ -0,0 +1,134 @@ +/* +Author: Hardik Shah +Email: hardik05@gmail.com +Web: http://hardik05.wordpress.com +*/ + +//a vulnerable c program to explain common vulnerability types +//fuzz with AFL + +#include +#include +#include + +struct Image +{ + char header[4]; + int width; + int height; + char data[10]; +}; + +void stack_operation(){ + char buff[0x1000]; + while(1){ + stack_operation(); + } +} + +int ProcessImage(char* filename){ + FILE *fp; + struct Image img; + + fp = fopen(filename,"r"); //Statement 1 + + if(fp == NULL) + { + printf("\nCan't open file or file doesn't exist.\r\n"); + exit(0); + } + + + while(fread(&img,sizeof(img),1,fp)>0) + { + //if(strcmp(img.header,"IMG")==0) + //{ + printf("\n\tHeader\twidth\theight\tdata\t\r\n"); + + printf("\n\t%s\t%d\t%d\t%s\r\n",img.header,img.width,img.height,img.data); + + + //integer overflow 0x7FFFFFFF+1=0 + //0x7FFFFFFF+2 = 1 + //will cause very large/small memory allocation. + int size1 = img.width + img.height; + char* buff1=(char*)malloc(size1); + + //heap buffer overflow + memcpy(buff1,img.data,sizeof(img.data)); + free(buff1); + //double free + if (size1/2==0){ + free(buff1); + } + else{ + //use after free + if(size1/3 == 0){ + buff1[0]='a'; + } + } + + + //integer underflow 0-1=-1 + //negative so will cause very large memory allocation + int size2 = img.width - img.height+100; + //printf("Size1:%d",size1); + char* buff2=(char*)malloc(size2); + + //heap buffer overflow + memcpy(buff2,img.data,sizeof(img.data)); + + //divide by zero + int size3= img.width/img.height; + //printf("Size2:%d",size3); + + char buff3[10]; + char* buff4 =(char*)malloc(size3); + memcpy(buff4,img.data,sizeof(img.data)); + + //OOBR read bytes past stack/heap buffer + char OOBR = buff3[size3]; + char OOBR_heap = buff4[size3]; + + //OOBW write bytes past stack/heap buffer + buff3[size3]='c'; + buff4[size3]='c'; + + if(size3>10){ + //memory leak here + buff4=0; + } + else{ + free(buff4); + } + int size4 = img.width * img.height; + if(size4/2==0){ + //stack exhaustion here + stack_operation(); + } + else{ + //heap exhaustion here + char *buff5; + do{ + buff5 = (char*)malloc(size4); + }while(buff5); + } + free(buff2); + //} + //else + // printf("invalid header\r\n"); + + } + fclose(fp); + return 0; +} + +int main(int argc,char **argv) +{ + if (argc < 2) { + fprintf(stderr, "no input file\n"); + exit(-1); + } + ProcessImage(argv[1]); + return 0; +}