CVE-2021-29511Network attack vector

Denial of service via empty memory copy

Published May 12, 2021 · Updated Aug 3, 2024

Resource exhaustion in Rust EVM evm-core allows remote authenticated users to interrupt EVM execution through crafted opcodes. Memory::copy_large continues processing an empty value and expands memory toward the supplied offset or target size instead of returning without allocation. Execution of affected memory-operation opcodes is required, and the resulting excess allocation can exhaust memory and deny EVM execution.

CVSS severity6.5
Medium
EPSS probability1.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Rust EVM evm-core allows remote authenticated users to interrupt EVM execution through crafted opcodes. Memory::copy_large continues processing an empty value and expands memory toward the supplied offset or target size instead of returning without allocation. Execution of affected memory-operation opcodes is required, and the resulting excess allocation can exhaust memory and deny EVM execution.

The record

CVE
CVE-2021-29511
Published
May 12, 2021
Updated
Aug 3, 2024
Vendor
rust-ethereum
Product
Rust EVM
Classifications
CWE-770, T1499.003
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 12, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.21.1
  2. Affected versionversion== 0.22.0
  3. Affected versionversion== 0.23.0
  4. Affected versionversion== 0.24.0
  5. Affected versionversion== 0.25.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

rust-ethereum · Rust EVMversion=< 0.21.1; version== 0.22.0; version== 0.23.0; version== 0.24.0; version== 0.25.0

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.003Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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