Added challenges

Author: MEhrn00

tutorial_aslr/Dockerfile

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+FROM debian:latest
+
+RUN apt-get update -y \
+    && apt-get install -y xinetd \
+    && apt-get clean -y
+
+# Create challenge user
+RUN useradd -u 1000 -d /home/challenge -s /bin/bash challenge
+RUN mkdir /home/challenge
+
+# Pipe xinetd logs to docker logs
+RUN ln -sf /proc/1/fd/1 /var/log/challenge.log
+
+# Copy xinetd and other dependencies
+COPY deps/challenge.xinetd /etc/xinetd.d/challenge
+COPY deps/limits.conf /etc/security/limits.d/90-challenge.conf
+COPY deps/banner_fail /etc/banner_fail
+COPY deps/entrypoint.sh /entrypoint.sh
+
+RUN chmod 551 entrypoint.sh
+
+# Set up chroot
+RUN mkdir /home/challenge/usr
+RUN cp -R /lib* /home/challenge && \
+    cp -R /usr/lib* /home/challenge/usr
+
+RUN mkdir /home/challenge/dev && \
+    mknod /home/challenge/dev/null c 1 3 && \
+    mknod /home/challenge/dev/zero c 1 5 && \
+    mknod /home/challenge/dev/random c 1 8 && \
+    mknod /home/challenge/dev/urandom c 1 9 && \
+    chmod 666 /home/challenge/dev/*
+
+RUN mkdir /home/challenge/bin && \
+    mkdir /home/challenge/etc && \
+    cp /bin/* /home/challenge/bin && \
+    cp /etc/shadow /home/challenge/etc && \
+    cp /etc/passwd /home/challenge/etc && \
+    rm /home/challenge/bin/rm
+
+# Set up challenge and flag
+WORKDIR /home/challenge
+COPY aslr .
+COPY flag.txt .
+
+RUN chmod 444 flag.txt
+RUN chmod 111 aslr
+
+RUN chown -R root:root /home/challenge
+
+CMD ["/entrypoint.sh"]
+
+EXPOSE 9999

tutorial_aslr/README.md

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+# Tutorial: ASLR
+
+## Category: Binary Exploitation
+
+## Description
+```
+The tutorial set of challenges are basic binary exploitation challenges designed to teach people various binary exploitation techniques. The recommended order to complete these challenges is ret2win, ROP, Shellcode, Canary, ASLR. These challenges can be completed without downloading and analyzing the binaries; however, they have been provided. If you need help with any of these challenges, feel free to reach out in the Discord.
+```
+
+### Flag: flag{342db1252faa6a2984b4935e0b4f1455}
+
+---
+# Docker
+Run the challenge with docker.  
+```bash
+$ docker build -t tutorial_aslr .
+$ docker run -p 9999:9999 tutorial_aslr
+```
+Connect with netcat.
+```bash
+$ nc localhost 9999
+```

tutorial_aslr/aslr

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+Connection FAILED: Too many concurrent connections from your IP address.

tutorial_aslr/deps/banner_fail

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+service challenge
+{
+    disable     = no
+    socket_type = stream
+    protocol    = tcp
+    wait        = no
+    user        = root
+    type        = UNLISTED
+    port        = 9999
+    bind        = 0.0.0.0
+
+    server      = /usr/sbin/chroot
+    server_args = --userspec=challenge:challenge /home/challenge ./aslr
+
+    # Logging
+    log_type       = FILE /var/log/challenge.log
+    log_on_failure = HOST
+    banner_fail    = /etc/banner_fail
+}

tutorial_aslr/deps/challenge.xinetd

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+#!/bin/sh
+
+/etc/init.d/xinetd start;
+trap : TERM INT; sleep infinity & wait

tutorial_aslr/deps/entrypoint.sh

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+# ulimit limit settings
+
+* hard nproc 50

tutorial_aslr/deps/limits.conf

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+flag{342db1252faa6a2984b4935e0b4f1455}

tutorial_aslr/flag.txt

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+#ifndef LIBVISUALIZE_H
+#define LIBVISUALIZE_H
+
+// Color definitions
+#define COLOR_RED       "\x1b[31m"
+#define COLOR_GREEN     "\x1b[32m"
+#define COLOR_BLUE      "\x1b[34m"
+#define COLOR_YELLOW    "\x1b[33m"
+#define COLOR_RESET     "\x1b[0m"
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+
+static uint64_t *canary = NULL;
+
+void visualize_stack();
+
+#endif

tutorial_aslr/includes/libvisualize.h

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+SOURCES=$(shell ls ./src/*.c)
+LDFLAGS:=
+CFLAGS:=-fno-stack-protector
+TARGET:=aslr
+CC:=gcc
+
+.PHONY: all clean $(TARGET)
+
+all: $(TARGET)
+
+clean:
+	rm -f $(TARGET)
+
+$(TARGET): $(SOURCES)
+	$(CC) -o $(TARGET) $(CFLAGS) -I./includes $(SOURCES) $(LDFLAGS)