Stack overflows can occur with precisions for integers and floats.
Proof of concepts:
- curl_mprintf("%d, %.*1$d", 500, 1);
- curl_mprintf("%d, %+0500.*1$f", 500, 1);
Ideally, compile with -fsanitize=address which makes this undefined
behavior a bit more defined for debug purposes.
The format strings are valid. The overflows occur due to invalid
arguments. If these arguments are variables with contents controlled
by an attacker, the function's stack can be corrupted.
Also see CVE-2016-9586 which partially fixed the float aspect.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Closes https://github.com/curl/curl/pull/5722
Windows does not allow setting the locale with environment variables (as
the test attempted to do), so the test failed when run with a user
locale that has a comma as radixchar. Changed the test to call
setlocale() explicitly to ensure that a known working locale is set even
on Windows.
Prior to this change a width arg could be erroneously output, and also
width and precision args could not be used together without crashing.
"%0*d%s", 2, 9, "foo"
Before: "092"
After: "09foo"
"%*.*s", 5, 2, "foo"
Before: crash
After: " fo"
Test 557 is updated to verify this and more
Following commit 0aafd77fa4, replaced the internal usage of
FORMAT_OFF_T and FORMAT_OFF_TU with the external versions that we
expect API programmers to use.
This negates the need for separate definitions which were subtly
different under different platforms/compilers.
This reverts renaming and usage of lib/*.h header files done
28-12-2012, reverting 2 commits:
f871de0... build: make use of 76 lib/*.h renamed files
ffd8e12... build: rename 76 lib/*.h files
This also reverts removal of redundant include guard (redundant thanks
to changes in above commits) done 2-12-2013, reverting 1 commit:
c087374... curl_setup.h: remove redundant include guard
This also reverts renaming and usage of lib/*.c source files done
3-12-2013, reverting 3 commits:
13606bb... build: make use of 93 lib/*.c renamed files
5b6e792... build: rename 93 lib/*.c files
7d83dff... build: commit 13606bbfde follow-up 1
Start of related discussion thread:
http://curl.haxx.se/mail/lib-2013-01/0012.html
Asking for confirmation on pushing this revertion commit:
http://curl.haxx.se/mail/lib-2013-01/0048.html
Confirmation summary:
http://curl.haxx.se/mail/lib-2013-01/0079.html
NOTICE: The list of 2 files that have been modified by other
intermixed commits, while renamed, and also by at least one
of the 6 commits this one reverts follows below. These 2 files
will exhibit a hole in history unless git's '--follow' option
is used when viewing logs.
lib/curl_imap.h
lib/curl_smtp.h
All C and H files now (should) feature the proper project curl source
code header, which includes basic info, a copyright statement and some
basic disclaimers.
Daniel Stenberg