The module is fuzzing UEFI Variable interface. The module is using UEFI SetVariable interface to write new UEFI variables to SPI flash NVRAM with randomized name/attributes/GUID/data/size. Note: this module modifies contents of non-volatile SPI flash memory (UEFI Variable NVRAM). This may render system unbootable if firmware doesn’t properly handle variable update/delete operations.
Usage:
“chipsec_main -m tools.uefi.uefivar_fuzz [-a <options>]“
Options:
“[-a <test>,<iterations>,<seed>,<test_case>]“
– “test“ which UEFI variable interface to fuzz “(all, name, guid, attrib, data, size)“
– “iterations“ number of tests to perform (default = 1000)
– “seed“ RNG seed to use
– “test_case“ test case # to skip to (combined with seed, can be used to skip to failing test)
All module arguments are optional
Examples:
>>> chipsec_main.py -m tools.uefi.uefivar_fuzz
>>> chipsec_main.py -m tools.uefi.uefivar_fuzz -a all,100000
>>> chipsec_main.py -m tools.uefi.uefivar_fuzz -a data,1000,123456789
>>> chipsec_main.py -m tools.uefi.uefivar_fuzz -a name,1,123456789,94
https://github.com/chipsec/chipsec/blob/master/chipsec/modules/tools/uefi/uefivar_fuzz.py
Firmware Security 