CVE-2021-29511

Name: CVE-2021-29511
Creator: NVD / NIST
Published: 2021-05-12T18:15:08.527+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 1.28%

Last modified Jun 17, 2026

CVE-2021-29511 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. evm is a pure Rust implementation of Ethereum Virtual Machine. Prior to the patch, when executing specific EVM opcodes related to memory operations that use `evm_core::Memory::copy_large`, the `evm` crate can over-allocate memory when it is not needed, making it possible for an attacker to perform denial-of-service attack. EPSS estimates a 1.28% chance of exploitation in the next 30 days.

Description

evm is a pure Rust implementation of Ethereum Virtual Machine. Prior to the patch, when executing specific EVM opcodes related to memory operations that use `evm_core::Memory::copy_large`, the `evm` crate can over-allocate memory when it is not needed, making it possible for an attacker to perform denial-of-service attack. The flaw was corrected in commit `19ade85`. Users should upgrade to `==0.21.1, ==0.23.1, ==0.24.1, ==0.25.1, >=0.26.1`. There are no workarounds. Please upgrade your `evm` crate version.

Metrics

CVSS 3.1

6.5/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

1.28%

66.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Evm Project	Evm	<= 0.21.0
Evm Project	Evm	0.22.0
Evm Project	Evm	0.23.0
Evm Project	Evm	0.24.0
Evm Project	Evm	0.25.0
Evm Project	Evm	0.26.0

References

https://crates.io/crates/evmThird Party Advisory
https://github.com/rust-blockchain/evm/commit/19ade858c430ab13eb562764a870ac9f8506f8ddPatch, Third Party Advisory
https://github.com/rust-blockchain/evm/security/advisories/GHSA-4jwq-572w-4388Patch, Third Party Advisory
https://crates.io/crates/evmThird Party Advisory
https://github.com/rust-blockchain/evm/commit/19ade858c430ab13eb562764a870ac9f8506f8ddPatch, Third Party Advisory
https://github.com/rust-blockchain/evm/security/advisories/GHSA-4jwq-572w-4388Patch, Third Party Advisory

Timeline

Published: May 12, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-29511?

How severe is CVE-2021-29511?

CVE-2021-29511 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 1.28% probability of exploitation in the next 30 days.

How do I fix CVE-2021-29511?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-29511?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST