Cross-Site Scripting vulnerability in @backstage/plugin-auth-backend

中 6.1CVE-2021-43776 · GHSA-w7fj-336r-vw49 · 26/11/2021 公開 · 17/06/2026 更新

要点

CVE-2021-43776 は auth backend (linuxfoundation), @backstage/plugin-auth-backend に影響する深刻度「中」 (CVSS 6.1) の脆弱性です。
今後30日間に悪用される確率（EPSS）：0.68%（全脆弱性の 52.3% より高い）。
対処：0.4.9 以降に更新してください。

パッケージ	影響を受けるバージョン	修正済みバージョン
auth backend linuxfoundation	`< 0.4.9`	`0.4.9`
@backstage/plugin-auth-backend npm	`< 0.4.9`	`0.4.9`

概要

Impact

This vulnerability 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.

Patches

This is vulnerability is patched in version 0.4.9 of @backstage/plugin-auth-backend.

For more information

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NVD の説明

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`.