// For flags

CVE-2021-41101

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

Severity Score

5.7
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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).

wire-server es un back end de código abierto para Wire, una plataforma de colaboración segura. Versiones anteriores a 2.106.0, el encabezado CORS "Access-Control-Allow-Origin" establecida por "nginz" se establece para todos los subdominios de ".wire.com" (incluyendo "wire.com"). Esto significa que si alguien encontrara un vector de tipo XSS en cualquiera de los subdominios, podría usarlo para hablar con la API de Wire usando la Cookie del usuario. No se presenta un parche, pero sí una solución. Para asegurarse de que un compromiso de un subdominio no da acceso a la cookie de otro, es posible limitar el encabezado "Access-Control-Allow-Origin" a las aplicaciones que realmente requieren la cookie (account-pages, team-settings y la webapp)

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
Single
Confidentiality
Partial
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-09-15 CVE Reserved
  • 2021-09-30 CVE Published
  • 2023-04-23 EPSS Updated
  • 2024-08-04 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC
References (1)
URL Tag Source
https://github.com/wireapp/wire-server/security/advisories/GHSA-v7xx-cx8m-g66p Third Party Advisory
URL Date SRC
URL Date SRC
URL Date SRC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Wire
Search vendor "Wire"
 Wire Server
Search vendor "Wire" for product "Wire Server"
 < 2.106.0
Search vendor "Wire" for product "Wire Server" and version " < 2.106.0"
-
Affected