Author: Bryan Bishop 2018-07-02 23:03:13
Published on: 2018-07-02T23:03:13+00:00
The Bitcoin alert system has been retired due to vulnerabilities that were previously unknown until the code was inspected for vulnerabilities prior to releasing the Alert Key. The vulnerabilities in the alert system could allow an attacker with an Alert Key to perform a Denial of Service (DoS) attack on nodes that still support the Alert system by sending very large alerts or filling the map with many integers, causing the node to run out of memory and crash.However, less than 4% of Bitcoin nodes are vulnerable, and the Bitcoin Core developers have created a "final alert" which is a maximum ID number alert that overrides all previous alerts and displays a fixed "URGENT: Alert key compromised, upgrade required" message on all vulnerable software. While the final alert is supposed to be uncancellable, it unfortunately can be cancelled due to the order of actions when processing an alert.To mitigate the risks associated with the vulnerabilities in the alert system, the Bitcoin Core developers have decided to completely retire the system and disclose its keys. The risks to those nodes affected by the vulnerabilities are minor, and the Bitcoin Core developers believe that it is safe to publish the Alert Key.It should be noted that altcoins that still use the Alert system are recommended to limit the number of alerts, the size of setCancel and setSubVer, and only allow one final alert altogether. Outdated node software is still vulnerable. A patch on top of Bitcoin Core 0.11 fixes these issues.The disclosure regarding the vulnerabilities in the Bitcoin alert system was primarily authored by Bryan Bishop (kanzure) and Andrew Chow (achow101). They also proposed not disclosing private keys in WIF format to prevent users from importing and reusing them in their wallet key circulation.
Updated on: 2023-06-13T03:40:20.789587+00:00