[New-bugs-announce] [issue15905] Copy to fixed size buffer w/o check in sys_update_path

[Christian Heimes]

New submission from Christian Heimes:

In Python/sysmodule.c the function sys_update_path() uses wcscpy to copy data to a fixed size buffer. The input comes from an external source (argv[0]) and could theoretically be larger than the buffer.

Suggested solution:
Increase the buffer a bit:

    wchar_t argv0copy[sizeof(wchar_t)* (MAXPATHLEN+1)];

and use wcsncpy:

    wcsncpy(argv0copy, argv0, MAXPATHLEN);
    argv0copy[MAXPATHLEN] = L'\0';


CID 486850

----------
components: Interpreter Core
messages: 170200
nosy: christian.heimes
priority: normal
severity: normal
stage: needs patch
status: open
title: Copy to fixed size buffer w/o check in sys_update_path
type: behavior
versions: Python 3.2, Python 3.3, Python 3.4

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue15905>
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