Beebug - A Tool For Checking Exploitability


beebug is a tool that can be used to verify if a program crash could be exploitable.
This tool was presented the first time at r2con 2018 in Barcelona.
Some implemented functionality are:
  • Stack overflow on libc
  • Crash on Program Counter
  • Crash on branch
  • Crash on write memory
  • Heap vulnerabilities
  • Read access violation (some exploitable cases)
  • Help to analyze a crash (graph view)

Dependencies
  • r2pipe
  • pydot
  • graphviz
  • pyqtgraph

Installation
~ $ wget https://github.com/radare/radare2/archive/2.7.0.tar.gz
~ $ tar xzvf 2.7.0.tar.gz
~ $ cd radare2-2.7.0/
~/radare2-2.7.0 $ ./configure --prefix=/usr
~/radare2-2.7.0 $ make -j8
~/radare2-2.7.0 $ sudo make install
# apt-get install graphviz
# pip3 install -r requirements.txt

Usage

help
$ python3 ./beebug.py -h
usage: beebug.py [-h] [-t TARGET] [-a TARGETARGS] [-f FILE] [-g GRAPH] [-i]
[-r REPORT_FILE] [-v]

optional arguments:
-h, --help show this help message and exit
-t TARGET, --target TARGET
target program to analyze
-a TARGETARGS, --targetargs TARGETARGS
arguments for the target program
-f FILE, --file FILE input file
-g GRAPH, --graph GRAPH
generate the graph
-i, --instrumentation
instrumentation option
-r REPORT_FILE, --report_file REPORT_FILE
DynamoRIO report file to parse

Simple usage
# python3 ./beebug.py -t tests/crash_on_pc
Process with PID 7691 started...
File dbg:///home/invictus1306/Documents/r2conf/beebug/beebug/tests/crash_on_pc reopened in read-write mode
= attach 7691 7691
child stopped with signal 11
[+] SIGNAL 11 errno=0 addr=0x00601038 code=2 ret=0
Crash on PC - Generally it is exploitable, the PC could be tainted
backtrace
0 0x601038 sp: 0x0 0 [??] obj.foo obj.foo0
1 0x4004f1 sp: 0x7ffdfa75d8e8 0 [sym.main] main+27
2 0x7f2669d00830 sp: 0x7ffdfa75d908 32 [??] r11+240
3 0x7f266a0ba7cb sp: 0x7ffdfa75d998 144 [??] sym.dl_rtld_di_serinfo+29051
4 0x400409 sp: 0x7ffdfa75d9c8 48 [??] entry0+41
registers
rax = 0x00601038
rbx = 0x00000000
rcx = 0x00000000
rdx = 0x7ffdfa75d9f8
r8 = 0x00400570
r9 = 0x7f266a0baab0
r10 = 0x00000846
r11 = 0x7f2669d00740
r12 = 0x004003e0
r13 = 0x7ffdfa75d9e0
r14 = 0x00000000
r15 = 0x00000000
rsi = 0x7ffdfa75d9e8
rdi = 0x0000000a
rsp = 0x7ffdfa75d8e8
rbp = 0x7ffdfa75d900
rip = 0x00601038
rflags = 0x00010206
orax = 0xffffffffffffffff

Graph generation
# python3 ./beebug.py -t tests/crash_on_pc -g crash_on_pc
...
$ display crash_on_pc.png


Report parsing
Parse the report produced by functrace, and graph generation.

Generate report using libtrace
$ drrun -c libfunctrace.so -report_file ./tests/reports/report1 -disas_func main -- ./tests/reports/simple_test
Please enter a message:
AAAA
Hello! This is the default message, the number is 22

Run beebug for graph generation
$ python3 beebug.py -i -r ./tests/reports/report1 -g tests/reports/report1
beebugreport

Future direction
  • Support different architectures
  • Improvement of the graph view (based on radare2)
  • Analyze core dumps (based on radare2)
  • Use instrumentation for the graph view generation

Lead Developer


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