Auth bypass in Ruby-Lang Ruby

CVE-2019-16201

WEBrick::HTTPAuth::DigestAuth in Ruby through 2.4.7, 2.5.x through 2.5.6, and 2.6.x through 2.6.4 has a regular expression Denial of Service cause by looping/backtracking. A victim must expose a WEBrick server that uses DigestAuth to the Internet or a untrusted network.

Vulnerability class: Broken Authentication

EPSS: 0.051 (91.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2019-16201?
CVE-2019-16201 is a high-severity vulnerability in Ruby-Lang Ruby, classified under Improper Authentication. CVSS score: 7.5/10. Published 2019-11-26.
How severe is CVE-2019-16201?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2019-16201 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.