CVE-2021-41101

CORS `Access-Control-Allow-Origin` settings are too lenient

MEDIUM
5.7
CVSS Score
Published: September 30, 2021 at 07:20 PM UTC
Updated: June 17, 2026 at 04:07 AM UTC
2 products affected across 2 vendorsWire ServerWire Server

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Severity
MEDIUM5.7
Exploit prediction
EPSS 0.7%

Description

wire-server is an open-source back end for Wire, a secure collaboration platform. Before version 2.106.0, the CORS ` Access-Control-Allow-Origin ` header set by `nginz` is set for all subdomains of `.wire.com` (including `wire.com`). This means that if somebody were to find an XSS vector in any of the subdomains, they could use it to talk to the Wire API using the user's Cookie. A patch does not exist, but a workaround does. To make sure that a compromise of one subdomain does not yield access to the cookie of another, one may limit the `Access-Control-Allow-Origin` header to apps that actually require the cookie (account-pages, team-settings and the webapp).

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.106.0
Affected range stops below 2.106.0, so it looks safe — our inference, not a vendor statement
v < 2.106.0
Affected range stops below 2.106.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

5.7MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-79

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