# CVE-2021-28878: Memory corruption in n/a

> A memory safety violation in the Rust standard library's Zip implementation allows attackers to potentially execute arbitrary code or cause denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 11 Apr 2021
- **Updated:** 3 Aug 2024
- **Also known as:** DEBIAN-CVE-2021-28878, GHSA-p39x-6cjx-6mpm, UBUNTU-CVE-2021-28878

## What is CVE-2021-28878?

CVE-2021-28878 is a high-severity memory corruption vulnerability in Fedoraproject Fedora, published on 11 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2021-28878?

It affects 2 products.


Products: Fedoraproject Fedora, Rust-Lang Rust.

## How do I fix CVE-2021-28878?

Upgrade to a fixed version.

## Is CVE-2021-28878 being exploited?

There is no known exploitation of CVE-2021-28878 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-28878 and fix it if it is affected.

What it is: CVE-2021-28878 is a high-severity memory corruption vulnerability in Fedoraproject Fedora, published on 11 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-28878 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2021-28878/ (Markdown: https://insights.sbomify.com/CVE-2021-28878/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-28878
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-28878
- OSV: https://osv.dev/vulnerability/CVE-2021-28878

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-28878/
Summaries are generated and may contain mistakes; the official description above is the record.