From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.org/gmane.linux.lib.musl.general/12017 Path: news.gmane.org!.POSTED!not-for-mail From: Rich Felker Newsgroups: gmane.linux.lib.musl.general,gmane.comp.security.oss.general Subject: Re: [oss-security] CVE request: musl libc 1.1.16 and earlier dns buffer overflow Date: Thu, 19 Oct 2017 21:25:47 -0400 Message-ID: <20171020012547.GT1627@brightrain.aerifal.cx> References: <20171019201757.GA31838@brightrain.aerifal.cx> Reply-To: musl@lists.openwall.com NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: blaine.gmane.org 1508462773 17720 195.159.176.226 (20 Oct 2017 01:26:13 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 20 Oct 2017 01:26:13 +0000 (UTC) User-Agent: Mutt/1.5.21 (2010-09-15) Cc: Felix Wilhelm , musl@lists.openwall.com To: oss-security@lists.openwall.com Original-X-From: musl-return-12030-gllmg-musl=m.gmane.org@lists.openwall.com Fri Oct 20 03:26:08 2017 Return-path: Envelope-to: gllmg-musl@m.gmane.org Original-Received: from mother.openwall.net ([195.42.179.200]) by blaine.gmane.org with smtp (Exim 4.84_2) (envelope-from ) id 1e5M4T-0002k3-TE for gllmg-musl@m.gmane.org; Fri, 20 Oct 2017 03:25:58 +0200 Original-Received: (qmail 27699 invoked by uid 550); 20 Oct 2017 01:26:01 -0000 Mailing-List: contact musl-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Original-Received: (qmail 27653 invoked from network); 20 Oct 2017 01:26:00 -0000 Content-Disposition: inline In-Reply-To: <20171019201757.GA31838@brightrain.aerifal.cx> Original-Sender: Rich Felker Xref: news.gmane.org gmane.linux.lib.musl.general:12017 gmane.comp.security.oss.general:23449 Archived-At: On Thu, Oct 19, 2017 at 04:17:57PM -0400, Rich Felker wrote: > Felix Wilhelm has discovered a flaw in the dns response parsing for > musl libc 1.1.16 that leads to overflow of a stack-based buffer. > Earlier versions are also affected. > > When an application makes a request via getaddrinfo for both IPv4 and > IPv6 results (AF_UNSPEC), an attacker who controls or can spoof the > nameservers configured in resolv.conf can reply to both the A and AAAA > queries with A results. Since A records are smaller than AAAA records, > it's possible to fit more addresses than the precomputed bound, and a > buffer overflow occurs. > > Users are advised to upgrade to 1.1.17 or patch; the patch is simple > and should apply cleanly to all recent versions: > > https://git.musl-libc.org/cgit/musl/patch/?id=45ca5d3fcb6f874bf5ba55d0e9651cef68515395 > > Users who cannot patch or upgrade immediately can mitigate the issue > by running a caching nameserver on localhost and pointing resolv.conf > to 127.0.0.1. CVE-2017-15650 has been assigned for this issue. Rich