CVE-2020-28501 Regular Expression Denial of Service (ReDoS)
Attackers can cause denial of service by supplying long user agent strings to the es6-crawler-detect library, triggering expensive regex operations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-28501?
CVE-2020-28501 is a medium-severity denial of service vulnerability in es6-crawler-detect, published on 22 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
This affects the package es6-crawler-detect before 3.1.3. No limitation of user agent string length supplied to regex operators.
Which versions are affected by CVE-2020-28501?
2 open source packages ship an affected version, including es6-crawler-detect. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
es6-crawler-detect npm | All versions | 3.1.3 |
es6-crawler-detect npm | All versions | 3.1.3 |
Products include Crawlerdetect Project Crawlerdetect.
How do I fix CVE-2020-28501?
Upgrade es6-crawler-detect to 3.1.3 or later.
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-2020-28501 being exploited?
There is no known exploitation of CVE-2020-28501 in the wild and no public exploit code.
Sources
Also known as GHSA-jxg6-fhwc-9v9c.