Security readout for executives and security teams
Plain-English summary
CVE-2021-29511 is a denial-of-service flaw in the Rust evm crate. Certain memory-related EVM operations can cause unnecessary memory over-allocation, potentially exhausting resources and disrupting systems that execute attacker-influenced EVM code.
Executive priority
Handle as a targeted availability risk. It is not a data theft issue, but exposed EVM execution services could be disrupted. Patch during the next urgent dependency maintenance cycle, sooner for internet-facing or customer-triggered execution paths.
Technical view
The issue affects rust-blockchain evm versions before 0.21.1 and specific vulnerable releases 0.22.0, 0.23.0, 0.24.0, and 0.25.0. The CVE maps to CWE-770 and has CVSS 6.5 because availability can be heavily impacted without affecting confidentiality or integrity.
Likely exposure
Exposure is most likely in Rust services, blockchain tooling, test harnesses, or platforms embedding the evm crate to execute untrusted or user-submitted EVM bytecode. Organizations not using this crate are not exposed based on the provided sources.
Exploitation context
The sources describe possible denial of service through specific memory-operation opcodes, but do not cite public exploitation, proof-of-concept activity, or CISA KEV listing. Treat exploit evidence as incomplete rather than confirmed active exploitation.
Researcher notes
Focus analysis on call paths reaching evm_core::Memory::copy_large through memory-related EVM opcodes. Validate version resolution across direct and transitive dependencies. The correcting commit is 19ade85; sources do not provide a workaround or confirmed exploitation telemetry.
Mitigation direction
- Upgrade evm to 0.21.1, 0.23.1, 0.24.1, 0.25.1, or at least 0.26.1.
- Prioritize systems executing untrusted or externally submitted EVM code.
- Check vendor advisory and release notes before deploying dependency updates.
- Do not rely on workarounds; the advisory states none are available.
Validation and detection
- Inventory Rust dependency manifests and lockfiles for evm versions.
- Confirm deployed artifacts use a fixed evm crate version.
- Identify services where external users can trigger EVM execution.
- Review monitoring for memory exhaustion or availability incidents in affected services.
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
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-770: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2021-29511 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/rust-blockchain/evm/security/advisories/GHSA-4jwq-572w-4388CVE reference · x_refsource_CONFIRM
- https://github.com/rust-blockchain/evm/commit/19ade858c430ab13eb562764a870ac9f8506f8ddCVE reference · x_refsource_MISC
- https://crates.io/crates/evmCVE 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.
Allocation of Resources Without Limits or Throttling
Allocation of Resources Without Limits or Throttling represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.