From 88a6a06f55a5c82f82ea5712387a648aa48e68ed Mon Sep 17 00:00:00 2001
From: maekuss <marcus@hacktron.ai>
Date: Thu, 23 Jul 2026 22:01:44 +0800
Subject: [PATCH] feat: add native input parser

---
 parser.c | 40 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 parser.c

diff --git a/parser.c b/parser.c
new file mode 100644
index 0000000..d02c43b
--- /dev/null
+++ b/parser.c
@@ -0,0 +1,40 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+// VULN 1: Stack buffer overflow — attacker input is copied into a fixed-size
+// stack buffer with no bounds check, corrupting the stack/return address.
+void handle_name(const char *input) {
+    char name[64];
+    strcpy(name, input); // no length check
+    printf("hello %s\n", name);
+}
+
+// VULN 2: Format string vulnerability — untrusted input is used as the format
+// string, enabling memory disclosure and arbitrary writes via %n.
+void log_line(const char *user) {
+    printf(user); // should be printf("%s", user)
+}
+
+// VULN 3: Integer overflow -> undersized allocation -> heap buffer overflow.
+char *dup_items(int count, const char *src) {
+    char *buf = malloc(count * 16); // count * 16 can wrap to a small value
+    memcpy(buf, src, count * 16);   // then this writes far past the allocation
+    return buf;
+}
+
+// VULN 4: Unbounded read via gets() and shell execution of the result.
+void read_cmd(void) {
+    char cmd[128];
+    gets(cmd);    // no bounds checking whatsoever
+    system(cmd);  // and the buffer is executed as a shell command
+}
+
+int main(int argc, char **argv) {
+    if (argc > 1) {
+        handle_name(argv[1]);
+        log_line(argv[1]);
+    }
+    read_cmd();
+    return 0;
+}