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Some CORS middleware allow untrusted origins

Critical
jub0bs published GHSA-v84h-653v-4pq9 May 2, 2024

Package

gomod jub0bs/fcors (Go)

Affected versions

0.8.0

Patched versions

0.9.0

Description

Impact

Some CORS middleware (more specifically those created by specifying two or more origin patterns whose hosts share a proper suffix) incorrectly allow some untrusted origins, thereby opening the door to cross-origin attacks from the untrusted origins in question.

For example, specifying origin patterns https://foo.com and https://bar.com (in that order) would yield a middleware that would incorrectly allow untrusted origin https://barfoo.com.

Patches

Patched in v0.9.0.

Workarounds

None.

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

CVE ID

No known CVE

Weaknesses

Credits