Security readout for executives and security teams
Plain-English summary
CVE-2021-45699 concerns older Rust ckb crate versions before 0.40.0. The reported impact is severe for blockchain operators: a remote attacker may trigger a memory allocation failure in misbehavior tracking and potentially support a 51% attack against Nervos CKB.
Executive priority
Treat as high priority only where Nervos CKB infrastructure or the ckb Rust crate is present. The potential blockchain consensus impact is serious, but the supplied evidence does not show active exploitation.
Technical view
The issue involves inability to allocate memory for a misbehavior HashMap in the ckb crate before 0.40.0. The public description links this failure mode to possible remote consensus-level impact against the Nervos CKB blockchain. No CVSS, CWE, or detailed affected product metadata is provided.
Likely exposure
Exposure is likely limited to organizations running or building against ckb crate versions before 0.40.0, especially Nervos CKB node or infrastructure operators. The source bundle lists affected vendor/product as n/a, so dependency validation is necessary.
Exploitation context
The sources say remote attackers may be able to trigger the condition. There is no KEV listing and no cited evidence of active exploitation in the supplied bundle.
Researcher notes
The public data is sparse: no CVSS vector, CWE, detailed affected CPEs, or exploit evidence. Analysis should focus on dependency version confirmation and operational role of affected CKB nodes rather than generalized enterprise exposure.
Mitigation direction
- Upgrade ckb crate usage to version 0.40.0 or later.
- Check RustSec advisory guidance before planning remediation.
- Identify Nervos CKB nodes or services using bundled ckb dependencies.
- Prioritize externally reachable or consensus-participating blockchain infrastructure.
- Monitor vendor and RustSec channels for additional guidance.
Validation and detection
- Inventory Rust dependencies for ckb versions before 0.40.0.
- Review deployed Nervos CKB node versions and dependency manifests.
- Confirm remediated builds resolve ckb at 0.40.0 or later.
- Check whether exposed nodes participate in consensus-sensitive operations.
- Document findings because affected product metadata is incomplete.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CVE-2021-45699 mapping review
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Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://rustsec.org/advisories/RUSTSEC-2021-0108.htmlCVE reference · x_refsource_MISC
- https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/ckb/RUSTSEC-2021-0108.mdCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.