The Bitcoin Core team urges miners to update client software with the latest Bitcoin Core 0.16.3 version as soon as possible.
“A denial-of-service vulnerability (CVE-2018-17144) exploitable by miners has been discovered in Bitcoin Core versions 0.14.0 up to 0.16.2. It is recommended to upgrade any of the vulnerable versions to 0.16.3 as soon as possible,” states the security advisory.
The flaw affected the Bitcoin Core wallet software and could have been exploited by attackers to crash Bitcoin Core nodes running software versions 0.14.0 to 0.16.2.
The CVE-2018-17144 vulnerability is critical because by coordinating an attack through the Bitcoin miners it was possible to bring down the entire blockchain either by overflooding the block with duplicate transactions, resulting in blockage of transaction confirmation from other people or by flooding the nodes of the Bitcoin P2P network and saturating the bandwidth.
The bug seems to have been introduced in March 2017, but no one apparently has exploited the flaw in live attacks.
The flaw potentially affects all recent versions of the BTC system, but anyway, experts pointed out that a coordinated Distributed Denial of Service (DDoS) attack against Bitcoin blockchain is very expensive.
It has been estimated that a successful DDoS attack on the BTC network would cost miners 12.5 bitcoins ($80,000).
According to the change log of the latest version, the Bitcoin Core team also patched minor issues related to RPC and other APIs, to invalid error flags, to the consensus and documentation.
“If you are running an older version, shut it down. Wait until it has completely shut down (which might take a few minutes for older versions), then run the installer (on Windows) or just copy over `/Applications/Bitcoin-Qt` (on Mac) or `bitcoind`/`bitcoin-qt` (on Linux).” continues the note.
“The first time you run version 0.15.0 or newer, your chainstate database will be converted to a new format, which will take anywhere from a few minutes to half an hour, depending on the speed of your machine.”