CVE-2021-43138 Prototype Pollution in async
A prototype pollution vulnerability in the Async library allows malicious users to escalate privileges via the mapValues method.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-43138?
CVE-2021-43138 is a high-severity vulnerability in Fedoraproject Fedora, published on 6 Apr 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
In Async before 2.6.4 and 3.x before 3.2.2, a malicious user can obtain privileges via the mapValues() method, aka lib/internal/iterator.js createObjectIterator prototype pollution.
Weakness: CWE-1321
Which versions are affected by CVE-2021-43138?
4 open source packages ship an affected version, including async. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
async npm | From 2.0.0 | 2.6.4 |
async npm | From 2.0.0 | 2.6.4 |
async npm | From 3.0.0 | 3.2.2 |
async npm | From 3.0.0 | 3.2.2 |
Products include Async Project Async, Fedoraproject Fedora.
How do I fix CVE-2021-43138?
Upgrade async to a fixed version for your release line: 2.6.4 or 3.2.2.
Is CVE-2021-43138 being exploited?
There is no known exploitation of CVE-2021-43138 in the wild and no public exploit code.
Sources
Also known as CLSA-2026-1773101703, CLSA-2026-1782089824, CLSA-2026-1792369544, GHSA-fwr7-v2mv-hh25, ROOT-APP-NPM-CVE-2021-43138.