# CVE-2021-30456: RUSTSEC-2021-0052 - Multiple functions can cause double-frees

Source: https://junglewise.ai/threats/cve-2021-30455-double-free-in-id-map  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-02-26  
License: CC BY 4.0 with a link back

CVE-2021-30456 · Severity: low · CVSS 3.1 · Published 2021-02-26

Multiple functions can cause double-frees

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

## Quick answers

**Is CVE-2021-30456 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2021-30456 being exploited in the wild.

**How severe is CVE-2021-30456?** Low severity, with a CVSS score of 3.1, published 26 February 2021.

**Which products and versions are affected?** id-map (crates.io) SEMVER:introduced=0,last_affected=0.2.1, SEMVER:introduced=0.0.0-0.

**Is there a fix for CVE-2021-30456?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2021-30456?** Check whether you run id-map (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.

## Affected products

- id-map (crates.io) SEMVER:introduced=0,last_affected=0.2.1, SEMVER:introduced=0.0.0-0

## Identifiers

- CVE-2021-30456
- CVE-2021-30455
- CVE-2021-30457
- GHSA-8gmx-cpcg-f8h5
- GHSA-rccq-j2m7-8fwr
- GHSA-vfqx-hv88-f9cv
- RUSTSEC-2021-0052

## Related threats

- [IdMap from_iter may lead to uninitialized memory being freed on drop](https://junglewise.ai/threats/idmap-from-iter-may-lead-to-uninitialized-memory-being-freed-on-drop-d3c786c0)
- [RUSTSEC-2025-0050 - IdMap::from_iter may lead to uninitialized memory being freed on drop](https://junglewise.ai/threats/rustsec-2025-0050-idmap-from-iter-may-lead-to-uninitialized-memory-72090de8)