Black-box testing of web applications with client-side code evaluation
Detecting security vulnerabilities in web applications by interacting with a web application at a computer server during its execution at the computer server, identifying client-side instructions provided by the web application responsive to an interaction with the web application, where the client-side instructions are configured to be implemented by a client computer that receives the client-side instructions from the computer server, evaluating the identified client-side instructions, and identifying a security vulnerability associated with the client-side instructions.
1. A system for detecting security vulnerabilities in web applications, the system comprising:
at least one hardware processor, wherein
the at least one hardware processor includes a block-box tester, and a client-side evaluator,
the black-box tester is configured to
interact with a web application at a computer server during its execution at the computer server, and
identify client-side instructions provided by the web application responsive to an interaction with the web application,
the client-side instructions are configured to be implemented by a client computer that receives the client-side instructions from the computer server; and
the client-side evaluator is configured to
evaluate the client-side instructions identified by the black-box tester, and
identify a security vulnerability associated with the client-side instructions.
2. The system of claim 1 where
the black-box tester is configured to identify a security vulnerability associated with the web application.
3. The system of claim 1 where
the client-side evaluator is configured to perform static analysis of the client-side instructions identified by the black-box tester to identify the security vulnerability associated with the client-side instructions.
4. The system of claim 1 where
the client-side evaluator is configured to perform dynamic taint analysis on the client-side instructions to track taint propagation within the client-side instructions, thereby identifying the security vulnerability associated with the client-side instructions.
5. The system of claim 4 where
the client-side evaluator is configured to modify the client-side instructions identified by the black-box tester to store information indicating whether variables within the client-side instructions point to tainted objects, and where
the client-side evaluator is configured to perform dynamic taint analysis on the modified client-side instructions to track taint propagation within the modified client-side instructions, thereby identifying the security vulnerability associated with the client-side instructions.
6. The system of claim 4 where
the client-side evaluator is configured to use a predefined security specification to determine which objects within the client-side instructions are tainted and how taint propagates from variable to variable within the client-side instructions.
7. The system of claim 4 and further comprising
an interpreter configured to track any variable within the client-side instructions that directly points to a tainted object within the client-side instructions, where
the client-side evaluator is configured to perform dynamic taint analysis on the client-side instructions by calling the interpreter to track taint propagation within the client-side instructions, thereby identifying the security vulnerability associated with the client-side instructions.
8. The system of claim 7 where
the interpreter is configured to track any variable that ultimately depends from any variable within the client-side instructions that directly points to a tainted object within the client-side instructions.
9. The system of claim 7 where
the interpreter is configured to use a predefined security specification to determine which objects within the client-side instructions are tainted and how taint propagates from variable to variable within the client-side instructions.
10. The system of claim 4 and further comprising
a symbolic analyzer configured to perform symbolic analysis of the client-side instructions to determine at least one value for at least one variable within the client-side instructions that would result in a control flow target being reached within the client-side instructions during execution of the client-side instructions, where
the client-side evaluator is configured to use any value determined by the symbolic analyzer when performing the dynamic taint analysis on the client-side instructions to cause the target control flow.
11. A computer program product for detecting security vulnerabilities in web applications, the computer program product comprising:
a computer-readable storage medium; and
computer-readable program code embodied in the computer-readable storage medium, where the computer-readable program code is configured to
interact with a web application at a computer server during its execution at the computer server,
identify client-side instructions provided by the web application responsive to an interaction with the web application, where
the client-side instructions are configured to be implemented by a client computer that receives the client-side instructions from the computer server,
evaluate the client-side instructions, and
identify a security vulnerability associated with the client-side instructions, wherein
the computer-readable storage medium is not a transitory, propagating signal per se.
12. The computer program product of claim 11 where
the computer-readable program code is configured to identify a security vulnerability associated with the web application.
13. The computer program product of claim 11 where
the computer-readable program code is configured to perform static analysis of the client-side instructions to identify the security vulnerability associated with the client-side instructions.
14. The computer program product of claim 11 where
the computer-readable program code is configured to perform dynamic taint analysis on the client-side instructions to track taint propagation within the client-side instructions, thereby identifying the security vulnerability associated with the client-side instructions.
15. The computer program product of claim 14 where
the computer-readable program code is configured to
modify the client-side instructions to store information indicating whether variables within the client-side instructions point to tainted objects, and
perform dynamic taint analysis on the modified client-side instructions to track taint propagation within the modified client-side instructions, thereby identifying the security vulnerability associated with the client-side instructions.