Bugtraq mailing list archives
Re: VNC Security Bulletin - zlib double free issue (multiple vendors and versions)
From: Anthony DeRobertis <asd () suespammers org>
Date: Fri, 5 Apr 2002 05:21:19 -0500
On Friday, April 5, 2002, at 03:13 AM, Andrew van der Stock wrote:
Apple's statement is: "Mac OS X and Mac OS X Server do not contain thisvulnerability." Does MacOS X and MacOS X Server even have a copy of zlib(ie libz.so) by default? Or is down to the FreeBSD malloc / free behavior of MacOS X? Hard to say - not a lot of information to go on.
I'm pretty sure it's the FreeBSD behavior that protects it because: Mac OS X includes libz: /System/Library/Frameworks/JavaVM.framework/Versions/1.3.1/Libraries/libzip. jnilib /usr/lib/libz.1.1.3.dylib /usr/lib/libz.1.dylib /usr/lib/libz.dylibThe following program does not crash, and indeed produces the warning messages that FreeBSD describes it should:
#include <stdlib.h> int main() { void *ptr; int x; for (x = 0; x < 10000; ++x) { ptr = malloc(123456); free(ptr); free(ptr); } return 0; } It produces these warnings:*** malloc[27202]: Deallocation of a pointer not malloced: 0x84000; This could be a double free(), or free() called with the middle of an allocated block; Try setting environment variable MallocHelp to see tools to help debug
(many, many times)
Current thread:
- VNC Security Bulletin - zlib double free issue (multiple vendors and versions) Andrew van der Stock (Apr 02)
- Re: VNC Security Bulletin - zlib double free issue (multiple vendors and versions) Anthony DeRobertis (Apr 05)
- RE: VNC Security Bulletin - zlib double free issue (multiple vendors and versions) Andrew van der Stock (Apr 05)
- Re: VNC Security Bulletin - zlib double free issue (multiple vendors and versions) Anthony DeRobertis (Apr 05)
- Re: VNC Security Bulletin - zlib double free issue (multiple vendors and versions) Nick Lamb (Apr 08)
- RE: VNC Security Bulletin - zlib double free issue (multiple vendors and versions) Andrew van der Stock (Apr 05)
- Re: VNC Security Bulletin - zlib double free issue (multiple vendors and versions) Anthony DeRobertis (Apr 05)