ruby: Regular expression denial of service vulnerability of WEBrick's Digest authentication
Published Nov 26, 2019
7.5
HIGHCVSS 3.1
EPSS 5.13%
Description
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.
Affected products
No data.
No data.
Red Hat Enterprise Linux 8
ruby:2.5-8040020200923213910.522a0ee4
Fixed · RHSA-2021:2587
Red Hat Enterprise Linux 8
ruby:2.6-8040020210430142949.522a0ee4
Fixed · RHSA-2021:2588
Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions
ruby:2.6-8010020220201152941.c27ad7f8
Fixed · RHSA-2022:0581
Red Hat Enterprise Linux 8.2 Extended Update Support
ruby:2.6-8020020220201131207.4cda2c84
Fixed · RHSA-2022:0582
Red Hat Software Collections for Red Hat Enterprise Linux 7
rh-ruby25-ruby-0:2.5.9-9.el7
Fixed · RHSA-2021:2104
Red Hat Software Collections for Red Hat Enterprise Linux 7
rh-ruby26-ruby-0:2.6.7-119.el7
Fixed · RHSA-2021:2230
Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS
rh-ruby25-ruby-0:2.5.9-9.el7
Fixed · RHSA-2021:2104
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS
rh-ruby25-ruby-0:2.5.9-9.el7
Fixed · RHSA-2021:2104
Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS
rh-ruby26-ruby-0:2.6.7-119.el7
Fixed · RHSA-2021:2230
Red Hat 3scale API Management Platform 2
3amp-system
Will not fix
Red Hat Enterprise Linux 5
ruby
Out of support scope
Red Hat Enterprise Linux 6
ruby
Out of support scope
Red Hat Enterprise Linux 7
ruby
Will not fix
Red Hat Software Collections
rh-ruby24-ruby
Will not fix
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 8 | ruby:2.5-8040020200923213910.522a0ee4 | Fixed | RHSA-2021:2587 |
| Red Hat Enterprise Linux 8 | ruby:2.6-8040020210430142949.522a0ee4 | Fixed | RHSA-2021:2588 |
| Red Hat Enterprise Linux 8.1 Update Services for SAP Solutions | ruby:2.6-8010020220201152941.c27ad7f8 | Fixed | RHSA-2022:0581 |
| Red Hat Enterprise Linux 8.2 Extended Update Support | ruby:2.6-8020020220201131207.4cda2c84 | Fixed | RHSA-2022:0582 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | rh-ruby25-ruby-0:2.5.9-9.el7 | Fixed | RHSA-2021:2104 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7 | rh-ruby26-ruby-0:2.6.7-119.el7 | Fixed | RHSA-2021:2230 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.6 EUS | rh-ruby25-ruby-0:2.5.9-9.el7 | Fixed | RHSA-2021:2104 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS | rh-ruby25-ruby-0:2.5.9-9.el7 | Fixed | RHSA-2021:2104 |
| Red Hat Software Collections for Red Hat Enterprise Linux 7.7 EUS | rh-ruby26-ruby-0:2.6.7-119.el7 | Fixed | RHSA-2021:2230 |
| Red Hat 3scale API Management Platform 2 | 3amp-system | Will not fix | n/a |
| Red Hat Enterprise Linux 5 | ruby | Out of support scope | n/a |
| Red Hat Enterprise Linux 6 | ruby | Out of support scope | n/a |
| Red Hat Enterprise Linux 7 | ruby | Will not fix | n/a |
| Red Hat Software Collections | rh-ruby24-ruby | Will not fix | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
AV:N/AC:L/Au:N/C:N/I:N/A:C
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
Score over time
2021–2026- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Percentile over time
- EPSS v1
- EPSS v2
- EPSS v3
- EPSS v4
- EPSS v5
Table of values (22 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 5.13% (0.05128) | 92.14th | v5 (v2026.06.15) |
| Jun 15, 2026 | 4.99% (0.04990) | 91.08th | v5 (v2026.06.15) |
| Nov 21, 2025 | 0.60% (0.00605) | 68.77th | v4 (v2025.03.14) |
| Nov 18, 2025 | 8.91% (0.08911) | 91.72th | v4 (v2025.03.14) |
| Mar 30, 2025 | 0.45% (0.00446) | 60.58th | v4 (v2025.03.14) |
| Mar 29, 2025 | 1.48% (0.01481) | 69.17th | v4 (v2025.03.14) |
| Mar 17, 2025 | 0.45% (0.00446) | 61.38th | v4 (v2025.03.14) |
| Dec 12, 2024 | 0.72% (0.00717) | 81.20th | v3 (v2023.03.01) |
| Mar 21, 2024 | 0.66% (0.00661) | 79.14th | v3 (v2023.03.01) |
| Nov 2, 2023 | 0.94% (0.00935) | 81.33th | v3 (v2023.03.01) |
| Sep 30, 2023 | 0.82% (0.00819) | 79.86th | v3 (v2023.03.01) |
| Sep 15, 2023 | 0.84% (0.00844) | 80.13th | v3 (v2023.03.01) |
| May 8, 2023 | 0.71% (0.00707) | 77.49th | v3 (v2023.03.01) |
| Mar 7, 2023 | 0.55% (0.00547) | 73.91th | v3 (v2023.03.01) |
| Mar 6, 2023 | 1.54% (0.01537) | 74.52th | v2 (v2022.01.01) |
| Feb 23, 2023 | 1.54% (0.01537) | 74.48th | v2 (v2022.01.01) |
| Apr 1, 2022 | 1.54% (0.01537) | 72.41th | v2 (v2022.01.01) |
| Feb 4, 2022 | 19.29% (0.19291) | 93.75th | v2 (v2022.01.01) |
| Feb 3, 2022 | 12.15% (0.12147) | 88.71th | v1 |
| Jan 6, 2022 | 12.15% (0.12147) | 88.57th | v1 |
| Sep 1, 2021 | 2.99% (0.02989) | 81.00th | v1 |
| Apr 14, 2021 | 2.99% (0.02989) | 0.00th | v1 |
References (16)
- http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00041.html vendor-advisory
- https://access.redhat.com/security/cve/CVE-2019-16201 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=1773728 Issue Tracking
- https://hackerone.com/reports/661722 Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/11/msg00025.html Mailing ListThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2019/12/msg00009.html mailing-list
- https://lists.debian.org/debian-lts-announce/2020/08/msg00027.html mailing-list
- https://lists.debian.org/debian-lts-announce/2023/04/msg00033.html mailing-list
- https://nvd.nist.gov/vuln/detail/CVE-2019-16201
- https://seclists.org/bugtraq/2019/Dec/31 mailing-list
- https://seclists.org/bugtraq/2019/Dec/32 mailing-list
- https://security.gentoo.org/glsa/202003-06 vendor-advisory
- https://www.cve.org/CVERecord?id=CVE-2019-16201
- https://www.debian.org/security/2019/dsa-4587 vendor-advisory
- https://www.oracle.com/security-alerts/cpujan2020.html
- https://www.ruby-lang.org/en/news/2019/10/01/webrick-regexp-digestauth-dos-cve-2019-16201/
Change history (0)
No recorded changes yet.