From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 3C0A2B88 for ; Fri, 8 Nov 2019 15:08:58 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from zinan.dashjr.org (zinan.dashjr.org [192.3.11.21]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 98501196 for ; Fri, 8 Nov 2019 15:08:57 +0000 (UTC) Received: from [2001:470:5:265:a45d:823b:2d27:961c] (unknown [IPv6:2001:470:5:265:a45d:823b:2d27:961c]) (Authenticated sender: luke-jr) by zinan.dashjr.org (Postfix) with ESMTPSA id 7F28038A0DEA; Fri, 8 Nov 2019 15:08:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=dashjr.org; s=zinan; t=1573225736; bh=sQJC0SBQC8kfMYDwGhsOB+mIylFeToEYWhp24sRMBV4=; h=To:Subject:Cc:From:Date; b=oc2oc3oCIYcDt04oXqZ9z5YLyszTwbopa5cZlNDxjXVt4xIIn3msWpz7qvRjMSILD K+b+d4v9ugCe7+16pmmJ9j7F7RedNdL86Ft7IGt2sWYLza6Vli3gN4G0mZFzeJMJfK 8O/8EGyBZq2jKh15EUkKxNjsmF84AcGc+zab9g6k= To: bitcoin-dev@lists.linuxfoundation.org Content-Disposition: inline From: Luke Dashjr Date: Fri, 8 Nov 2019 15:07:36 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201911081507.40441.luke@dashjr.org> X-Spam-Status: No, score=-4.3 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Cc: security@bitcoincore.org Subject: [bitcoin-dev] CVE-2017-18350 disclosure X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Nov 2019 15:08:58 -0000 CVE-2017-18350 is a buffer overflow vulnerability which allows a malicious SOCKS proxy server to overwrite the program stack on systems with a signed `char` type (including common 32-bit and 64-bit x86 PCs). The vulnerability was introduced in 60a87bce873ce1f76a80b7b8546e83a0cd4e07a5 (SOCKS5 support) and first released in Bitcoin Core v0.7.0rc1 in 2012 Aug 27. A fix was hidden in d90a00eabed0f3f1acea4834ad489484d0012372 ("Improve and document SOCKS code") released in v0.15.1, 2017 Nov 6. To be vulnerable, the node must be configured to use such a malicious proxy in the first place. Note that using *any* proxy over an insecure network (such as the Internet) is potentially a vulnerability since the connection could be intercepted for such a purpose. Upon a connection request from the node, the malicious proxy would respond with an acknowledgement of a different target domain name than the one requested. Normally this acknowledgement is entirely ignored, but if the length uses the high bit (ie, a length 128-255 inclusive), it will be interpreted by vulnerable versions as a negative number instead. When the negative number is passed to the recv() system call to read the domain name, it is converted back to an unsigned/positive number, but at a much wider size (typically 32-bit), resulting in an effectively infinite read into and beyond the 256-byte dummy stack buffer. To fix this vulnerability, the dummy buffer was changed to an explicitly unsigned data type, avoiding the conversion to/from a negative number. Credit goes to practicalswift (https://twitter.com/practicalswift) for discovering and providing the initial fix for the vulnerability, and Wladimir J. van der Laan for a disguised version of the fix as well as general cleanup to the at-risk code. Timeline: - 2012-04-01: Vulnerability introduced in PR #1141. - 2012-05-08: Vulnerability merged to master git repository. - 2012-08-27: Vulnerability published in v0.7.0rc1. - 2012-09-17: Vulnerability released in v0.7.0. ... - 2017-09-21: practicalswift discloses vulnerability to security team. - 2017-09-23: Wladimir opens PR #11397 to quietly fix vulernability. - 2017-09-27: Fix merged to master git repository. - 2017-10-18: Fix merged to 0.15 git repository. - 2017-11-04: Fix published in v0.15.1rc1. - 2017-11-09: Fix released in v0.15.1. ... - 2019-06-22: Vulnerability existence disclosed to bitcoin-dev ML. - 2019-11-08: Vulnerability details disclosure to bitcoin-dev ML.