// For flags

CVE-2021-43776

XSS vulnerability in @backstage/plugin-auth-backend

Severity Score

6.1
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

Backstage is an open platform for building developer portals. In affected versions the auth-backend plugin allows a malicious actor to trick another user into visiting a vulnerable URL that executes an XSS attack. This attack can potentially allow the attacker to exfiltrate access tokens or other secrets from the user's browser. The default CSP does prevent this attack, but it is expected that some deployments have these policies disabled due to incompatibilities. This is vulnerability is patched in version `0.4.9` of `@backstage/plugin-auth-backend`.

Backstage es una plataforma abierta para construir portales para desarrolladores. En las versiones afectadas, el plugin auth-backend permite a un actor malicioso engañar a otro usuario para que visite una URL vulnerable que ejecute un ataque de tipo XSS. Este ataque puede permitir al atacante exfiltrar tokens de acceso u otros secretos del navegador del usuario. El CSP por defecto previene este ataque, pero se espera que algunas implementaciones tengan estas políticas deshabilitadas debido a incompatibilidades. Esta vulnerabilidad está parcheada en la versión "0.4.9" de "@backstage/plugin-auth-backend"

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
None
Integrity
Partial
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-11-16 CVE Reserved
  • 2021-11-26 CVE Published
  • 2024-08-04 CVE Updated
  • 2024-08-11 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linuxfoundation
Search vendor "Linuxfoundation"
 Auth Backend
Search vendor "Linuxfoundation" for product "Auth Backend"
 < 0.4.9
Search vendor "Linuxfoundation" for product "Auth Backend" and version " < 0.4.9"
node.js
Affected