CVE-2021-43308 Exponential ReDoS in markdown-link-extractor
An attacker can cause a denial of service in applications using markdown-link-extractor by supplying malicious input that triggers exponential regex backtracking.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-43308?
CVE-2021-43308 is a medium-severity denial of service vulnerability in markdown-link-extractor, published on 1 Jun 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
An exponential ReDoS (Regular Expression Denial of Service) can be triggered in the markdown-link-extractor npm package, when an attacker is able to supply arbitrary input to the module's exported function
Weakness: CWE-1333
Which versions are affected by CVE-2021-43308?
4 open source packages ship an affected version, including markdown-link-extractor. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
markdown-link-extractor npm | All versions | 3.0.2 |
markdown-link-extractor npm | All versions | 3.0.2 |
markdown-link-extractor npm | From 4.0.0 | 4.0.1 |
markdown-link-extractor npm | From 4.0.0 | 4.0.1 |
Products include Markdown-Link-Extractor Project Markdown-Link-Extractor.
How do I fix CVE-2021-43308?
Upgrade markdown-link-extractor to a fixed version for your release line: 3.0.2 or 4.0.1.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-43308 being exploited?
There is no known exploitation of CVE-2021-43308 in the wild and no public exploit code.
Sources
Also known as GHSA-mmh6-m7v9-5956.