PT-2020-8890 · Caddy · Caddy

Sam James · Published 2020-06-15 · Updated 2022-10-06 · CVE-2018-21246

Positive Technologies (AI Summary)

CVSS v3.1

9.8

Critical

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Caddy versions prior to 0.10.13

Description The issue is related to the mishandling of TLS client authentication. This is caused by the lack of the StrictHostMatching mode, allowing an attacker to bypass TLS client authentication. An attacker may indicate an SNI during the TLS handshake that is different from the name in the HTTP Host header, which can lead to an authentication bypass.

Recommendations For versions prior to 0.10.13, update to version 0.10.13 or later to resolve the issue. As a temporary workaround, consider enabling the StrictHostMatching mode to minimize the risk of exploitation.

Fix

Improper Authentication

Weakness Enumeration

CWE-287

Related Identifiers

CVE-2018-21246

GHSA-GR7W-X2JP-3XGW

GO-2020-0043

Affected Products

Caddy

References · 12

• https://nvd.nist.gov/vuln/detail/CVE-2018-21246 · Security Note
• https://osv.dev/vulnerability/GO-2020-0043 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-gr7w-x2jp-3xgw · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2018-21246 · Vendor Advisory
• https://github.com/caddyserver/caddy · Note
• https://github.com/caddyserver/caddy/releases/tag/v0.10.13 · Note
• https://github.com/caddyserver/caddy/pull/2099 · Note
• https://github.com/caddyserver/caddy/commit/4d9ee000c8d2cbcdd8284007c1e0f2da7bc3c7c3 · Note
• https://t.me/cvenotify/4375 · Telegram Post
• https://pkg.go.dev/vuln/GO-2020-0043 · Note
• https://bugs.gentoo.org/715214 · Note
• https://t.me/cibsecurity/12749 · Telegram Post