oss-sec mailing list archives

Re: Re: CVE request: heap buffer overflow in glibc swscanf


From: Florian Weimer <fweimer () redhat com>
Date: Wed, 04 Feb 2015 10:42:41 +0100

On 02/04/2015 04:16 AM, cve-assign () mitre org wrote:
The check with __libc_use_alloca also checks against the number
of array entries to allocate rather than the number of bytes, so
the function can allocate up to four times as many bytes as is
libc policy on the stack in the wide character case.

Here, it seems that the goal of the policy is risk management for
use of alloca. This is security relevant for some applications that
use glibc, because it could (for example) allow a denial of service
attack that's intended to trigger a failed alloca. There was one
intended policy, and the the incorrect "__libc_use_alloca
(newsize)" caused a different (and weaker) policy to be enforced
instead.

If you want to assign CVE IDs for stack overflows in glibc without
demonstrated application impact, we really need to find a way to
streamline the process because there are quite a few missing assignments.

I wouldn't mind getting a pool of CVEs (for multiple years, going back
to around 2000), and assigning them to issues in the glibc Bugzilla
instance, and posting weekly summaries to oss-security.  Would that
work for you?

-- 
Florian Weimer / Red Hat Product Security


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