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authorAndrea Fioraldi <andreafioraldi@gmail.com>2020-02-03 13:11:10 +0100
committerAndrea Fioraldi <andreafioraldi@gmail.com>2020-02-03 13:11:10 +0100
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tree5c3e4e5829f45dce46794ebc2681732738d689fe /examples/argv_fuzzing/README.md
parente2eedefc65bec1a04605f117a11ca8bdf9d80323 (diff)
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move custom and pythoon mutators examples into examples/
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+# argvfuzz
+
+afl supports fuzzing file inputs or stdin. When source is available,
+`argv-fuzz-inl.h` can be used to change `main()` to build argv from stdin.
+
+`argvfuzz` tries to provide the same functionality for binaries. When loaded
+using `LD_PRELOAD`, it will hook the call to `__libc_start_main` and replace
+argv using the same logic of `argv-fuzz-inl.h`.
+
+A few conditions need to be fulfilled for this mechanism to work correctly:
+
+1. As it relies on hooking the loader, it cannot work on static binaries.
+2. If the target binary does not use the default libc's `_start` implementation
+   (crt1.o), the hook may not run.
+3. The hook will replace argv with pointers to `.data` of `argvfuzz.so`. If the
+   target binary expects argv to be living on the stack, things may go wrong.