Witness Block Parsing DoS Vulnerability

Description

Impact

All lnd nodes before version v0.15.4 are vulnerable to a block parsing bug that can cause a node to enter a degraded state once encountered. In this degraded state, nodes can continue to make payments and forward HTLCs, and close out channels. Opening channels is prohibited, and also on chain transaction events will be undetected.

This can cause loss of funds if a CSV expiry is researched during a breach attempt or a CLTV delta expires forgetting the funds in the HTLC.

Patches

A patch is available starting with lnd v0.15.4.

Workarounds

Nodes can use the lncli updatechanpolicy RPC call to increase their CLTV value to a very high amount or increase their fee policies. This will prevent nodes from routing through your node, meaning that no pending HTLCs can be present.

References

https://github.com/lightningnetwork/lnd/issues/7096

https://github.com/lightningnetwork/lnd/releases/tag/v0.15.4-beta

Basic information

Type
reviewed
Severity
high
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2022-11-18 18:50:01 UTC
Updated
2023-01-29 05:03:12 UTC
GitHub reviewed
2022-11-18 18:50:01 UTC
NVD published
2022-11-17

EPSS Score

Score Percentile
0.61% 69.51%

CVSS Scores

Base score Version Severity Vector
8.2 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

CWEs

CWE id Name
CWE-20 Improper Input Validation

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
go github.com/lightningnetwork/lnd < 0.15.4-beta 0.15.4-beta

References

cvelogic Threat Intelligence