CVE-2021-43776

mediumPriorität · verfolgen · 24EPSS 0.007 · 52. PerzentilEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.68% (52nd) EPSS

CVSS 4.3 · medium

Is it mine?

3 products

Prüfe deine Angriffsfläche

Who says so?

4 sources

cnnvd · enisa_euvd · nvd · osv

EPSS · bewertet 2026-10-28

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`.

cvss

Technischer Schweregrad, 0–10. Eine Zeile je Quelle.

7.4

010

Basiswert 0–10 · höher = schwerwiegender · Vektor überfahren zum Auflösen⚠ Quellen uneinig · medium–high · 4.3–7.4

v2.04.3mediumAV:N/AC:M/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USAusnutzbarkeit 8.6 · Auswirkung 2.9

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nprimary · NVD / NIST USAusnutzbarkeit 2.8 · Auswirkung 2.7

v3.17.4highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:Nsecondary · ENISA EU

v3.17.4highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:Nsecondary · security-advisories@github.comAusnutzbarkeit 2.8 · Auswirkung 4

v3.17.4highCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:Nsecondary · OSV

v3.15.6mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)

schwächen

Die CWE-Schwächeklassen, zu denen dies gehört.

CWE-79USCWE-79US

betroffene Produkte (3)

Betroffene Produkte und Versionsbereiche.

backstage backstage≤ < 0.4.9enisa_euvdEU
linuxfoundation auth backend< 0.4.9nvdUScpe:2.3:a:linuxfoundation:auth_backend:*:*:*:*:*:*:*:*
npm @backstage/plugin-auth-backend< 0.4.9osvUSpkg:npm/%40backstage/plugin-auth-backend

Advisories (1)

Hersteller- und Ökosystem-Meldungen dazu.

GHSA-w7fj-336r-vw49Cross-Site Scripting vulnerability in @backstage/plugin-auth-backend2021-12-01ghsa · osvUS
### 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 If you have any questions or comments about this advisory: * Open an issue in the [Backstage repository](https://github.com/backstage/backstage) * Visit our chat, linked to in [Backstage README](https://github.com/backstage/backstage)

auch bekannt als (3)

Weitere Namen und Kennungen dieser Entität.

quellen

Welche Quellen diesen Datensatz belegen und wann.

cnnvd enisa_euvd nvd osv NVD CVE.org MITRE

veröffentlicht 2021-11-26geändert 2026-06-17

Referenzen (7)

Externe Belege — Patches, Meldungen, Analysen.

scry

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