An issue was discovered in the ckb crate before 0.40.0 for Rust. Remote attackers may be able to conduct a 51% attack against the Nervos CKB blockchain by triggering an inability to allocate memory for the misbehavior HashMap.
Collected exploitation and prediction evidence
Risk source coverageCISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.
No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.
cve-program · CVE-2021-45699
PublishedAn issue was discovered in the ckb crate before 0.40.0 for Rust. Remote attackers may be able to conduct a 51% attack against the Nervos CKB blockchain by triggering an inability to allocate memory for the misbehavior HashMap.
- Source published
- 26 Dec 2021 21:49:25 UTC
- Source modified
- 4 Aug 2024 04:47:02 UTC
- Observed here
- 23 Oct 2026 15:48:27 UTC
- Source terms
- CVE Program Terms of Use
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euvd · EUVD-2022-0422
PublishedAn issue was discovered in the ckb crate before 0.40.0 for Rust. Remote attackers may be able to conduct a 51% attack against the Nervos CKB blockchain by triggering an inability to allocate memory for the misbehavior HashMap.
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Dec 26, 2021, 9:49:25 PM
dateUpdated: Aug 4, 2024, 4:47:02 AM
- Source published
- Dec 26, 2021, 9:49:25 PM (timezone not stated)
- Source modified
- Aug 4, 2024, 4:47:02 AM (timezone not stated)
- Observed here
- 9 Nov 2026 23:08:41 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.
nvd · CVE-2021-45699
PublishedAn issue was discovered in the ckb crate before 0.40.0 for Rust. Remote attackers may be able to conduct a 51% attack against the Nervos CKB blockchain by triggering an inability to allocate memory for the misbehavior HashMap.
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Modified
Weakness classifications: CWE-770
Original publisher date fields
published: 2021-12-27T00:15:09.623
lastModified: 2026-06-17T04:13:58.337
1 source CPE criteria · context only
- cpe:2.3:a:nervos:ckb:*:*:*:*:*:rust:*:*
The original JSON retains the logical configuration operators, exclusions and version bounds.
- Source published
- 27 Dec 2021 00:15:09 UTC
- Source modified
- 17 Jun 2026 04:13:58 UTC
- Observed here
- 24 Oct 2026 19:17:37 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS 3.1 · [email protected] · Primary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0 · [email protected] · Primary · 7.8 AV:N/AC:L/Au:N/C:N/I:N/A:C
osv · GHSA-2969-8hh9-57jc
PublishedAn issue was discovered in the ckb crate before 0.40.0 for Rust. Remote attackers may be able to conduct a 51% attack against the Nervos CKB blockchain by triggering an inability to allocate memory for the misbehavior HashMap.
- Source published
- 6 Jan 2022 22:09:49 UTC
- Source modified
- 8 Nov 2023 04:07:22 UTC
- Observed here
- 24 Oct 2026 13:19:54 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.
CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Publisher rating · HIGH
osv · GHSA-48vq-8jqv-gm6f
PublishedIn 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. An attack is trivial: 1. connect to another node 2. send an invalid sync protocol request, such as `SendHeaders` for non-consecutive blocks 3. disconnect 4. repeat
- Source published
- 25 Aug 2021 21:01:23 UTC
- Source modified
- 8 Nov 2023 04:07:22 UTC
- Observed here
- 24 Oct 2026 13:19:54 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.
Publisher rating · HIGH
osv · RUSTSEC-2021-0108
PublishedIn 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.
- Source published
- 25 Jul 2021 12:00:00 UTC
- Source modified
- 12 Oct 2026 18:00:05 UTC
- Observed here
- 24 Oct 2026 13:19:54 UTC
- Source terms
- OSV · upstream source license applies
Original source record · Cite this exact observation · Complete original publisher JSON
This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.