Privilege metric for evaluating the security of a library
A privilege metric application quantifies a privilege reduction for a subject software module M S . Target critical resources M t accessible by the subject module are identified. Permissions P(M S , M t ) for the subject module to access each of the target critical resources as a result of the privilege reduction are determined. Default library permissions P base (M S , M t ) without the privilege reduction are determined. A metric regarding the vulnerability reduction of P(M S , M t ) with respect to P base (M S , M t ) is quantified.
1. A system for providing a privilege reduction metric quantifying a privilege reduction definition provided by a privilege reduction system for a subject module M S , comprising:
program source code comprising a plurality of modules;
a plurality of third party libraries; and
a processor and a memory configured to store non-transitory instructions that, when executed by the processor, run a privilege metric application configured to:
identify a plurality of target critical resources M t accessible by the subject module;
determine permissions P(M S , M t ) for the subject module to access each of the plurality of target critical resources as a result of the privilege reduction;
determine default library permissions P base (M S , M t ) without the privilege reduction; and
quantify a metric regarding the vulnerability reduction of P(M S , M t ) with respect to P base (M S , M t ).
2. The system of claim 1 , wherein for the default library permissions any module has complete permissions on all exports of any other module.
3. The system of claim 1 , wherein the run privilege application is further configured to disallow all but whitelisted permissions at boundaries of the subject module.
4. The system of claim 3 , wherein the run privilege application is further configured to compile a privilege definition to a set of subject and target modules.
5. The system of claim 1 , wherein the run privilege application is further configured to receive a definition of the privilege reduction.
6. The system of claim 5 , wherein the privilege reduction comprises a metric of the permissions restricted by a privilege-reducing system.
7. A method by a computer based privilege metric application for quantifying a privilege reduction for a subject module M S , comprising the steps of:
identifying a plurality of target critical resources M t accessible by the subject module;
determining permissions P(M S , M t ) for the subject module to access each of the plurality of target critical resources as a result of the privilege reduction;
determining default library permissions P base (M S , M t ) without the privilege reduction; and
quantifying a metric regarding the vulnerability reduction of P(M S , M t ) with respect to P base (M S , M t ).
8. The method of claim 7 , wherein for the default library permissions any module has complete permissions on all exports of any other module.
9. The method of claim 7 , further comprising the step of disallowing all but whitelisted permissions at boundaries of the subject module.
10. The method of claim 9 , further comprising the step of compiling a privilege definition for a set of subject and target modules.
11. The method of claim 7 , further comprising the step of receiving a definition of the privilege reduction.
12. The method of claim 11 , wherein the privilege reduction comprises a metric of the permissions restricted by a privilege-reducing system.