From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id 2129342383 for ; Fri, 17 Dec 2021 20:54:24 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id D8F0068AF01; Fri, 17 Dec 2021 22:54:21 +0200 (EET) Received: from w4.tutanota.de (w4.tutanota.de [81.3.6.165]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 6C164680B71 for ; Fri, 17 Dec 2021 22:54:15 +0200 (EET) Received: from w3.tutanota.de (unknown [192.168.1.164]) by w4.tutanota.de (Postfix) with ESMTP id 95482106014E for ; Fri, 17 Dec 2021 20:54:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1639774454; s=s1; d=lynne.ee; h=From:From:To:To:Subject:Subject:Content-Description:Content-ID:Content-Type:Content-Type:Content-Transfer-Encoding:Content-Transfer-Encoding:Cc:Date:Date:In-Reply-To:In-Reply-To:MIME-Version:MIME-Version:Message-ID:Message-ID:Reply-To:References:References:Sender; bh=SKszfVN1p68gK89YIOYSH0YxKlpjcMRz6Ch+u8pI47I=; b=uucJfHB14Tx5jzh7iu2cn8H1GhhZ5gBrj3NOXbDIAC+XHS8p18FSBrjg9JX2MXgc 1eSEDuIX4vRc/JeGRyA64Pw8oA4n3H2Ia5nuJV7nGxfMu/T8Cmmsfs9aYw15Xm6UxOQ Fmd9qxs0KZVQQDMoVe9j8USeUiHnFImK1ALfo3Fx5giYoVPzheW1XheNkGlg3kswDmn seFG2Cixj7MLnvll3+VkeuZpD8UQuasNUv9I6lz4j4h/QEJ8l4LvPffTPxWk9vhIO/n yIjjR426wiC1u6A0Hfn1++Kw9kSr3qfV6cYx+pRU5+sCZiGWqV2aTPtfr4rnjWCcrow ovAVPsqjmQ== Date: Fri, 17 Dec 2021 21:54:14 +0100 (CET) From: Lynne To: FFmpeg development discussions and patches Message-ID: In-Reply-To: <163975114109.13029.10142418833883066194@lain.red.khirnov.net> References: <20211213054336.19783-1-pal@sandflow.com> <163947788654.13029.10298345109744593134@lain.red.khirnov.net> <163950889025.13443.18056291142265665105@lain.red.khirnov.net> <163959962513.13029.16441945709966296103@lain.red.khirnov.net> <163975114109.13029.10142418833883066194@lain.red.khirnov.net> MIME-Version: 1.0 Subject: Re: [FFmpeg-devel] [PATCH v10 1/2] avformat/imf: Demuxer X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: Dec 17, 2021, 3:25 PM by anton@khirnov.net: > Quoting Pierre-Anthony Lemieux (2021-12-15 21:41:25) > >> On Wed, Dec 15, 2021 at 12:20 PM Anton Khirnov wrote: >> > >> > Quoting Pierre-Anthony Lemieux (2021-12-15 01:17:26) >> > > > >> > > > Now the question is whether a malicious attacker can craft those two >> > > > files to get access to anything they shouldn't. I suppose at the very >> > > > least the attacker can get information that the user opened the file (by >> > > > adding an asset on an attacker's server) but that will be a danger with >> > > > any playlists allowing network resources and can be controlled with >> > > > io_open(). Can you think of any other possible issues? >> > > > >> > > >> > > Some security considerations: >> > > >> > > - a DDoS can conceivably occur if a malicious CPL+ASSETMAP is widely >> > > distributed. Both an ASSETMAP and a CPL are required since (a) the CPL >> > > does not contain paths/hyperlinks and (b) only those resources >> > > referenced by the CPL are fetched using the ASSETMAP. >> > > - the CPL uses XML, which has its own security considerations. For >> > > example, XML parsing can result in entities being fetched over the >> > > network, but this is disabled by default in libxml AFAIK. >> > >> > This is concerning. From a brief glance at libxml2, it seems that you >> > need to pass XML_PARSE_NONET as the last parameter to xmlReadMemory() to >> > actually disabling network fetching. >> > But it is possible I'm misreading the code, so if you or anyone else >> > understands this better then clarifications are welcome. >> >> I was referring to entity expansion and the loading of DTDs being >> disabled by default -- see XML_PARSE_NOENT and XML_PARSE_DTDLOAD at >> [1-2]. >> > > Okay then. If nobody has further comments, I will push your latest patch > in a few days. > I think this shouldn't get merged into 5.0. It would get minimal amount of fuzzing if it does now, so let's leave it for a later release? I'd still like to see libuuid being used, we have several uses for it already. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".