Prior to 0.11.0-beta, LND (Lightning Network Daemon) had a vulnerability in its invoice database. While claiming on-chain a received HTLC output, it didn’t verify that the corresponding outgoing off-chain HTLC was already settled before releasing the preimage. In the case of a hash-and-amount collision with an invoice, the preimage for an expected payment was instead released. A malicious peer could have deliberately intercepted an HTLC intended for the victim node, probed the preimage through a colluding relayed HTLC, and stolen the intercepted HTLC. The impact is a loss of funds in certain situations, and a weakening of the victim’s receiver privacy.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26896
Reference (s):
- https://gist.github.com/ariard/6bdeb995565d1cc292753e1ee4ae402d
- https://lists.linuxfoundation.org/pipermail/lightning-dev/2020-October/002855.html
- https://lists.linuxfoundation.org/pipermail/lightning-dev/2020-October/002857.html