Re: Buffer Overflow

From: Ryan Reilly (rreilly_at_redhawkgaming.com)
Date: 11/05/03

  • Next message: Cobus Neethling: "RE: bill gates' claim about security vulnerabilities per LOC inUnix versus Windows" 
    Date: Tue, 04 Nov 2003 17:02:30 -0800
To: secprog@securityfocus.com

    Pablo,

    I assume you're talking about Delphi here. The option that will affect
    buffer overflows is the Range Checking option. This will prevent buffer
    overflows in array and string functions as long as you aren't using long
    string types (which are enabled by default as "string"). Fat lot of
    good that does.

    It also doesn't handle the case where you pass input into other
    libraries, such as system API's. Additionally, it slows your program
    down. So, while it may be a good tool for testing, I wouldn't rely on
    it to secure your code.

    As for the other two options, setting them makes your program throw
    exceptions on I/O errors, or integer overflow. If you don't catch the
    exceptions, the attacker has still achieved a DoS.

    cheers,
    Ryan Reilly

    pablo gietz wrote:

    > Hi Secprogrammers
    >
    > Here my stupid question.
    > If I compile my final build with the checkboxes:
    > - Range checking ( Checks that array and string subscripts are within
    > bounds. Corresponds to {$R}) .
    > - I/O checking (Checks for I/O errors after every I/O call.
    > Corresponds to {$I}.)
    > - Overflow checking ( Checks overflow for integer operations.
    > Corresponds to {$Q}.)
    >
    > checked . Could this minimize the possibility of occurrences of buffer
    > overflows or other similar security holes?
    >
    >
    > Thanks
    >

  • Next message: Cobus Neethling: "RE: bill gates' claim about security vulnerabilities per LOC inUnix versus Windows"

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