Skip to main content
← All vulnerabilities
CVE-2023-39910

The cryptocurrency wallet entropy seeding mechanism used in Libbitcoin Explorer 3.0.0 through 3.6.0 is weak, aka the Milk Sad issue.

Published
Last modified
published
Not listed in CISA KEV
3 proofs of concept on GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: partial

Summary

The cryptocurrency wallet entropy seeding mechanism used in Libbitcoin Explorer 3.0.0 through 3.6.0 is weak, aka the Milk Sad issue. The use of an mt19937 Mersenne Twister PRNG restricts the internal entropy to 32 bits regardless of settings. This allows remote attackers to recover any wallet private keys generated from "bx seed" entropy output and steal funds. (Affected users need to move funds to a secure new cryptocurrency wallet.) NOTE: the vendor's position is that there was sufficient documentation advising against "bx seed" but others disagree. NOTE: this was exploited in the wild in June and July 2023.

Timeline

  1. CVE published
  2. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: partial

  3. Record last updated

Affected versions

  • n/a n/a

    Version range not reported

References 9

GitHub · libbitcoin/libbitcoin-explorer

GitHub · libbitcoin/libbitcoin-system

milksad.info

news.ycombinator.com

GitHub · Xaxis/bitcoin-security

GitHub · demining/RAMnesia-Attack

GitHub · z1ph1us/MilkSad-Mnemonic-Generator