CVE-2021-28878

Name: CVE-2021-28878
Creator: NVD / NIST
Published: 2021-04-11T20:15:12.813+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 2.00%

Last modified Jun 17, 2026

CVE-2021-28878 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. In the standard library in Rust before 1.52.0, the Zip implementation calls __iterator_get_unchecked() more than once for the same index (under certain conditions) when next_back() and next() are used together. This bug could lead to a memory safety violation due to an unmet safety requirement for the TrustedRandomAccess trait.. EPSS estimates a 2.00% chance of exploitation in the next 30 days.

Description

In the standard library in Rust before 1.52.0, the Zip implementation calls __iterator_get_unchecked() more than once for the same index (under certain conditions) when next_back() and next() are used together. This bug could lead to a memory safety violation due to an unmet safety requirement for the TrustedRandomAccess trait.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

2.00%

78.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-119

Affected Software

Vendor	Product	Versions
Rust-Lang	Rust	< 1.52.0
Fedoraproject	Fedora	32
Fedoraproject	Fedora	33
Fedoraproject	Fedora	34

References

https://github.com/rust-lang/rust/issues/82291Exploit, Issue Tracking, Third Party Advisory
https://github.com/rust-lang/rust/pull/82292Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CZ337CM4GFJLRDFVQCGC7J25V65JXOG5/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TFUO3URYCO73D2Q4WYJBWAMJWGGVXQO4/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VZG65GUW6Z2CYOQHF7T3TB5CZKIX6ZJE/
https://security.gentoo.org/glsa/202210-09Third Party Advisory
https://github.com/rust-lang/rust/issues/82291Exploit, Issue Tracking, Third Party Advisory
https://github.com/rust-lang/rust/pull/82292Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CZ337CM4GFJLRDFVQCGC7J25V65JXOG5/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TFUO3URYCO73D2Q4WYJBWAMJWGGVXQO4/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VZG65GUW6Z2CYOQHF7T3TB5CZKIX6ZJE/
https://security.gentoo.org/glsa/202210-09Third Party Advisory

Timeline

Published: Apr 11, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-28878?

How severe is CVE-2021-28878?

CVE-2021-28878 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 2.00% probability of exploitation in the next 30 days.

How do I fix CVE-2021-28878?

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-2021-28878?

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

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Source: NVD / NIST