oss-sec mailing list archives
Re: Re: CVE Request: dhcpcd 3.x, potentially other versions too
From: Seth Arnold <seth.arnold () canonical com>
Date: Tue, 1 Dec 2015 23:58:11 -0800
On Tue, Dec 01, 2015 at 11:58:47PM -0500, cve-assign () mitre org wrote:
MITRE will assign CVE IDs. Do the above references mean that most of the changed code lines in dhcp.c.patch correspond to out-of-bounds reads shown in the http://roy.marples.name/projects/dhcpcd/fdiff?sbs=1&v1=63689c50411b0920&v2=dad877391ea5b128 diff,
I had expected this part of the diff to address the out-of-bounds writes: if (out && out != start) *(out - 1) = ' ';
the change from "(l = *q++)" to "(l = *q++) && q - p < len" corresponds to an out-of-bounds write,
I must confess that I skimmed the protected code block quickly when coming to the conclusion that this was out-of-bounds reads -- it's intricate and involved and the q - p < len check looked correct. But the memcpy(out,...) call does look like it'd also perform out-of-bounds writes.
the deletion of "free (dhcp->dnssearch)" corresponds to a use-after-free, and nothing else in the 2012 part of the http://roy.marples.name reference is a new vulnerability? (This is just a guess.)
I should point out that it's my summary that it's a use-after-free -- Guido said in his report that it is a double-free.
The reason we're asking this and not immediately sending three CVE IDs is that someone at MITRE will ultimately use, or at least consider using, both https://launchpadlibrarian.net/228152582/dhcp.c.patch and http://roy.marples.name/projects/dhcpcd/finfo?name=dhcp.c&ci=27a92c6a825d6e74 to describe what the CVEs mean. If there's already information about the equivalences between these references, that will make this process easier, and also further confirm that three IDs is the right number.
I'm afraid the MITRE crew has a more difficult task than we do. Thanks
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Current thread:
- CVE Request: dhcpcd 3.x, potentially other versions too Seth Arnold (Dec 01)
- Re: CVE Request: dhcpcd 3.x, potentially other versions too cve-assign (Dec 01)
- Re: Re: CVE Request: dhcpcd 3.x, potentially other versions too Seth Arnold (Dec 01)
- Re: Re: CVE Request: dhcpcd 3.x, potentially other versions too Sebastian Krahmer (Dec 02)
- Re: Re: CVE Request: dhcpcd 3.x, potentially other versions too Seth Arnold (Dec 01)
- Re: CVE Request: dhcpcd 3.x, potentially other versions too cve-assign (Dec 02)
- Re: CVE Request: dhcpcd 3.x, potentially other versions too cve-assign (Dec 01)