Answer in brief
CVE-2021-45699 records a Unknown severity vulnerability in Remote memory exhaustion in ckb. The current sources do not mark it as known exploited. The current feed maps ckb (crates.io). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps ckb (crates.io). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| ckbcrates.io | >=0.0.0-0 <0.40.0 | 0.40.0 |
Published upstream
Jul 25, 2021
Evidence: source:osv:source_dates:source-dates:recordSource modified
Oct 12, 2026
Evidence: source:osv:source_dates:source-dates:recordFirst seen by HOL
Oct 12, 2026
In the ckb sync protocol, SyncState maintains a HashMap called 'misbehavior' that keeps a score of a peer's violations of the protocol. This HashMap is keyed to PeerIndex (an alias for SessionId), and entries are never removed from it. SessionId is an integer that increases monotonically with every new connection. A remote attacker can manipulate this HashMap to grow forever, resulting in degraded performance and ultimately a panic on allocation failure or being killed by the OS, depending on the platform. This is a critical severity security bug. It could be exploited to create a targeted or network-wide denial of service, to reduce the hash power of the network as part of a 51% attack, and perhaps in other creative ways.
Quoted source text, attributed separately from HOL analysis.