# CVE-2020-35861: RUSTSEC-2020-0006 - Flaw in `realloc` allows reading unknown memory

Source: https://junglewise.ai/threats/cve-2020-35861-out-of-bounds-read-in-bumpalo  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2020-03-24  
License: CC BY 4.0 with a link back

CVE-2020-35861 · Severity: low · CVSS 3.1 · Published 2020-03-24

Flaw in `realloc` allows reading unknown memory

Technologies: [bumpalo (crates.io)](https://junglewise.ai/threats/technologies/bumpalo). Vendors: [crates.io](https://junglewise.ai/threats/vendors/crates-io).

## Quick answers

**Is CVE-2020-35861 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2020-35861 being exploited in the wild.

**How severe is CVE-2020-35861?** Low severity, with a CVSS score of 3.1, published 24 March 2020.

**Which products and versions are affected?** bumpalo (crates.io) SEMVER:introduced=3.0.0,fixed=3.2.1.

**Is there a fix for CVE-2020-35861?** Yes. bumpalo (crates.io): upgrade to 3.2.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2020-35861?** Check whether you run bumpalo (crates.io) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- bumpalo (crates.io): upgrade to 3.2.1 or later

  ```sh
  cargo update -p bumpalo
  ```


## Affected products

- bumpalo (crates.io) SEMVER:introduced=3.0.0,fixed=3.2.1

## Identifiers

- CVE-2020-35861
- GHSA-vqx7-pw4r-29rr
- RUSTSEC-2020-0006

## Related threats

- [bumpalo has use-after-free due to a lifetime error in `Vec::into_iter()`](https://junglewise.ai/threats/bumpalo-has-use-after-free-due-to-a-lifetime-error-in-vec-into-iter-a79d9967)
- [RUSTSEC-2022-0078 - Use-after-free due to a lifetime error in `Vec::into_iter()`](https://junglewise.ai/threats/rustsec-2022-0078-use-after-free-due-to-a-lifetime-error-in-vec-into-800f8333)