CVE-2021-23364 Regular Expression Denial of Service (ReDoS)
Attackers can cause denial of service in applications using browserslist by providing specially crafted queries that trigger excessive CPU usage during parsing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-23364?
CVE-2021-23364 is a medium-severity denial of service vulnerability in browserslist, published on 28 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The package browserslist from 4.0.0 and before 4.16.5 are vulnerable to Regular Expression Denial of Service (ReDoS) during parsing of queries.
Weakness: CWE-1333
Which versions are affected by CVE-2021-23364?
2 open source packages ship an affected version, including browserslist. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
browserslist npm | From 4.0.0 | 4.16.5 |
browserslist npm | From 4.0.0 | 4.16.5 |
Products include Browserslist Project Browserslist.
How do I fix CVE-2021-23364?
Upgrade browserslist to 4.16.5 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-2021-23364 being exploited?
There is no known exploitation of CVE-2021-23364 in the wild and no public exploit code.
Sources
Also known as CLSA-2026-1774311645, CLSA-2026-1777163887, CLSA-2026-1788560456, DEBIAN-CVE-2021-23364, GHSA-w8qv-6jwh-64r5, ROOT-APP-NPM-CVE-2021-23364 and 1 more.