The CHECK macro in mrbgems/mruby-sprintf/src/sprintf.c in mruby 1.4.1 contains a signed integer overflow, possibly leading to out-of-bounds memory access because the mrb_str_resize function in string.c does not check for a negative length.

An issue was discovered in mruby 1.4.1. There is a heap-based buffer over-read associated with OP_ENTER because mrbgems/mruby-fiber/src/fiber.c does not extend the stack in cases of many arguments to fiber.

An issue was discovered in mruby 1.4.1. There is a NULL pointer dereference in mrb_class, related to certain .clone usage, because mrb_obj_clone in kernel.c copies flags other than the MRB_FLAG_IS_FROZEN flag (e.g., the embedded flag).

An issue was discovered in mruby 1.4.1. There is a NULL pointer dereference in mrb_class_real because "class BasicObject" is not properly supported in class.c.

The init_copy function in kernel.c in mruby 1.4.1 makes initialize_copy calls for TT_ICLASS objects, which allows attackers to cause a denial of service (mrb_hash_keys uninitialized pointer and application crash) or possibly have unspecified other impact.

In versions of mruby up to and including 1.4.0, a use-after-free vulnerability exists in src/io.c::File#initilialize_copy(). An attacker that can cause Ruby code to be run can possibly use this to execute arbitrary code.

In versions of mruby up to and including 1.4.0, an integer overflow exists in src/vm.c::mrb_vm_exec() when handling OP_GETUPVAR in the presence of deep scope nesting, resulting in a use-after-free. An attacker that can cause Ruby code to be run can use this to possibly execute arbitrary code.

The mark_context_stack function in gc.c in mruby through 1.2.0 allows attackers to cause a denial of service (heap-based use-after-free and application crash) or possibly have unspecified other impact via a crafted .rb file.