Remediation of security vulnerabilities in computer software

• US 9,298,926 B2
• Filed: 09/12/2013
• Issued: 03/29/2016
• Est. Priority Date: 10/09/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Tripp, Omer
• Primary Examiner(s): Mehrmanesh, Amir
• Assistant Examiner(s): RUPRECHT, CHRISTOPHER S
• Application Number:
  US14/024,730
• Publication Number:
  US 20140101769A1
• Time in Patent Office: 929 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 16/9024 Graphs; Linked lists G06F16/9027 takes precedence
• CPC Class Codes: G06F 21/12 Protecting executable software
• CPC Class Codes: G06F 21/52 during program execution, e.g. stack integrity ; Preventing unwanted data erasure; Buffer overflow
• CPC Class Codes: G06F 21/54 by adding security routines or objects to programs
• CPC Class Codes: G06F 21/57 Certifying or maintaining trusted computer platforms, e.g. secure boots or power-downs, version controls, system software checks, secure updates or assessing vulnerabilities
• CPC Class Codes: G06F 21/577 Assessing vulnerabilities and evaluating computer system security
• CPC Class Codes: G06F 21/6218 to a system of files or objects, e.g. local or distributed file system or database
• CPC Class Codes: G06F 2221/033 Test or assess software

Abstract

Processing a downgrader specification by constructing a set of candidate downgrader placement locations found within a computer software application, where each of the candidate downgrader placement locations corresponds to a transition between a different pair of instructions within the computer software application, and where each of the transitions participates in any of a plurality of data flows in a set of security-sensitive data flows within the computer software application, applying a downgrader specification to the set of candidate downgrader placement locations, and determining that the downgrader specification provides full coverage of the set of security-sensitive data flows within the computer software application if at least one candidate downgrader placement location within each of the security-sensitive data flows is a member of the set of candidate downgrader placement locations.

Claims

1. A method for processing a downgrader specification, the method comprising:

constructing a set of candidate downgrader placement locations found within a computer software application, wherein each of the candidate downgrader placement locations corresponds to a transition between a different pair of instructions within the computer software application, and wherein each of the transitions participates in any of a plurality of data flows in a set of security-sensitive data flows within the computer software application;

applying a downgrader specification to the set of candidate downgrader placement locations using a processor, wherein applying the downgrader specification comprises eliminating from the set of candidate downgrader placement locations any of the candidate downgrader placement locations whose elimination is indicated by the downgrader specification; and

determining that the downgrader specification provides full coverage of the set of security-sensitive data flows within the computer software application if at least one candidate downgrader placement location within each of the security-sensitive data flows is a member of the set of candidate downgrader placement locations.

2. The method according to claim 1 wherein membership of each of the candidate downgrader placement locations in the set of candidate downgrader placement locations is indicated by the downgrader specification.

3. The method according to claim 1 and further comprising receiving the downgrader specification after the downgrader specification is defined by a computer user.

4. The method according to claim 1 wherein the applying comprises applying wherein the downgrader specification indicates areas of the computer software application where downgraders are not to be placed.

5. The method according to claim 1 wherein the applying comprises applying wherein the downgrader specification indicates that downgraders be placed within a predefined number of instructions steps from a code location within the computer software application where untrusted data is read.

6. The method according to claim 1 wherein the applying comprises applying wherein the downgrader specification indicates that downgraders be placed within a predefined number of instruction steps from a security-sensitive operation within the computer software application.

7. A method for processing a downgrader specification, the method comprising:

constructing a set of candidate downgraders for processing a set of security-sensitive data flows within a computer software application, wherein each of the security-sensitive data flows is processable by at least one of the candidate downgraders;

applying a downgrader specification to the set of candidate downgraders using a processor, wherein applying the downgrader specification comprises eliminating from the set of candidate downgraders any of the candidate downgraders whose elimination is indicated by the downgrader specification; and

determining that the downgrader specification provides full coverage of the set of security-sensitive data flows within the computer software application if each of the security-sensitive data flows is processable by at least one of the candidate downgraders remaining in the set of candidate downgraders.

8. The method according to claim 7 wherein membership of each of the candidate downgraders in the set of candidate downgraders is indicated by the downgrader specification.

9. The method according to claim 7 and further comprising receiving the downgrader specification after the downgrader specification is defined by a computer user.

10. The method according to claim 7 wherein the applying comprises applying wherein the downgrader specification indicates specific downgraders from which the candidate downgraders are selectable.

11. The method according to claim 7 wherein the applying comprises applying wherein the downgrader specification indicates a maximum number of distinct downgraders in the set of candidate downgraders.

12. The method according to claim 7 wherein the applying comprises applying wherein the downgrader specification indicates whether any of validators and sanitizers are includable in the set of candidate downgraders.