Author: Aymeric Vitte 2019-11-08 19:40:17
Published on: 2019-11-08T19:40:17+00:00
In a recent email exchange on the Bitcoin-dev mailing list, concerns were raised about the use of SOCKS proxy for Tor as the main purpose for Bitcoin. The Tor network is not designed to handle peer-to-peer networks like Bitcoin and there are a lot of misbehaving/dangerous nodes there. A better alternative suggested was node-Tor, which is designed specifically for p2p, using the Tor protocol to add an internal missing encryption and anonymity layer to the Bitcoin protocol. The discussion then shifted to a disclosure of a buffer overflow vulnerability (CVE-2017-18350) that allowed a malicious SOCKS proxy server to overwrite the program stack on systems with a signed char type. To be vulnerable, the node must be configured to use such a malicious proxy in the first place. 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.Credit goes to 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. The timeline of the vulnerability dates back to its introduction in April 2012 and its eventual disclosure in June 2019.
Updated on: 2023-06-13T22:13:17.502940+00:00