Vulnerability in Libbitcoin Explorer
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. 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.
EPSS: 0.014 (69.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Libbitcoin Libbitcoin_explorer
- N/a — versions n/a
Weakness classification (CWE)
Public proof-of-concept exploits
- z1ph1us/MilkSad-Mnemonic-Generator
- demining/RAMnesia-Attack
- Xaxis/bitcoin-security
- Hitplus/RingSide-Replay-Attack
- Hitplus/hitplus.github.io
- HomelessPhD/MilkSad_
- PuddinCat/GithubRepoSpider
- demining/Milk-Sad-vulnerability-in-the-Libbitcoin-Explorer-3.x
- demining/Phoenix-Rowhammer-Attack-CVE-2025-6202
- plzheheplztrying/cve_
References
- cve@mitre.org (Third Party Advisory)
- cve@mitre.org (Third Party Advisory)
- cve@mitre.org (Third Party Advisory)
- cve@mitre.org (Third Party Advisory)
- cve@mitre.org (Third Party Advisory)
- cve@mitre.org
Frequently asked questions
- What is CVE-2023-39910?
- CVE-2023-39910 is a high-severity vulnerability in Libbitcoin Explorer, classified under Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG). CVSS score: 7.5/10. Published 2023-08-09.
- How severe is CVE-2023-39910?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2023-39910 known to be exploited?
- 12 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.