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Full vulnerability report · 2021
CVE-2021-41372High confidence

Power BI Report Server Spoofing Vulnerability

Microsoft · Power BI Report Server version 1.11.8091.10468

7.6HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2021-28400

No EUVD known-exploited evidence

A Cross-Site Scripting (XSS) and Cross-Site Request Forgery (CSRF) vulnerability exists when Power BI Report Server Template file (pbix) containing HTML files is uploaded to the server and HTML files are accessed directly by the victim. Combining these 2 vulnerabilities together, an attacker is able to upload malicious Power BI templates files to the server using the victim's session and run scripts in the security context of the user and perform privilege escalation in case the victim has admin privileges when the victim access one of the HTML files present in the malicious Power BI template uploaded. The security update addresses the vulnerability by helping to ensure that Power BI Report Server properly sanitize file uploads.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
7.6 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

A Cross-Site Scripting (XSS) and Cross-Site Request Forgery (CSRF) vulnerability exists when Power BI Report Server Template file (pbix) containing HTML files is uploaded to the server and HTML files are accessed directly by the victim. Combining these 2 vulnerabilities together, an attacker is able to upload malicious Power BI templates files to the server using the victim's session and run scripts in the security context of the user and perform privilege escalation in case the victim has admin privileges when the victim access one of the HTML files present in the malicious Power BI template uploaded. The security update addresses the vulnerability by helping to ensure that Power BI Report Server properly sanitize file uploads.

What

A Cross-Site Scripting (XSS) and Cross-Site Request Forgery (CSRF) vulnerability exists when Power BI Report Server Template file (pbix) containing HTML files is uploaded to the server and HTML files are accessed directly by the victim. Combining these 2 vulnerabilities together, an attacker is able to upload malicious Power BI templates files to the server using the victim's session and run scripts in the security context of the user and perform privilege escalation in case the victim has admin privileges when the victim access one of the HTML files present in the malicious Power BI template uploaded. The security update addresses the vulnerability by helping to ensure that Power BI Report Server properly sanitize file uploads.

Why

Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

What

A Cross-Site Scripting (XSS) and Cross-Site Request Forgery (CSRF) vulnerability exists when Power BI Report Server Template file (pbix) containing HTML files is uploaded to the server and HTML files are accessed directly by the victim. Combining these 2 vulnerabilities together, an attacker is able to upload malicious Power BI templates files to the server using the victim's session and run scripts in the security context of the user and perform privilege escalation in case the victim has admin privileges when the victim access one of the HTML files present in the malicious Power BI template uploaded. The security update addresses the vulnerability by helping to ensure that Power BI Report Server properly sanitize file uploads.

Why

Attacker-controlled content can reach a browser as executable script without sufficient output encoding or sanitisation.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may gain additional privileges.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') → gain additional privileges
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
Required interaction required
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Changed: exploitation can affect a different security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-79 ↗

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'). The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N/E:P/RL:O/RC:C

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UIRequiredUser interaction: Another user must perform an action for exploitation to succeed.SChangedScope: The attack can affect a component governed by a different security authority.CHighConfidentiality impact: A successful attack can cause a major loss.ILowIntegrity impact: A successful attack can cause a limited loss.ANoneAvailability impact: No direct loss is represented by this metric.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkPrivilege escalationCWE-79
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2021-28400Official EUVD mapping

A Cross-Site Scripting (XSS) and Cross-Site Request Forgery (CSRF) vulnerability exists when Power BI Report Server Template file (pbix) containing HTML files is uploaded to the server and HTML files are accessed directly by the victim. Combining these 2 vulnerabilities together, an attacker is able to upload malicious Power BI templates files to the server using the victim's session and run scripts in the security context of the user and perform privilege escalation in case the victim has admin privileges when the victim access one of the HTML files present in the malicious Power BI template uploaded. The security update addresses the vulnerability by helping to ensure that Power BI Report Server properly sanitize file uploads.

Official EUVD record
CERT-FR · French · CERTFR-2021-AVI-863Multiples vulnérabilités dans les produits Microsoft

fonctionnalité de sécurité. Solution Se référer au bulletin de sécurité de l'éditeur pour l'obtention des correctifs (cf. section Documentation). Documentation Bulletin de sécurité Microsoft du 09 novembre 2021 https://msrc.microsoft.com/update-guide/ Référence CVE CVE-2021-26444 https://www.cve.org/CVERecord?id=CVE-2021-26444 Référence CVE CVE-2021-3711 https://www.cve.org/CVERecord?id=CVE-2021-3711 Référence CVE CVE-2021-40442 https://www.cve.org/CVERecord?id=CVE-2021-40442 Référence CVE CVE-2021-41349 https://www.cve.org/CVERecord?id=CVE-2021-41349 Référence CVE CVE-2021-41368 https://www.cve.org/CVERecord?id=CVE-2021-41368 Référence CVE CVE-2021-41372 https://www.cve.org/CVERecord?id=CVE-2021-41372 Référence CVE CVE-2021-41373 https://www.cve.org/CVERecord?id=CVE-2021-41373 Référence CVE CVE-2021-41374 https://www.cve.org/CVERecord?id=CVE-2021-41374 Référence CVE CVE-2021-41375 https://www.cve.org/CVERecord?id=CVE-2021-41375 Référence CVE CVE-2021-41376 https://www.cve.org/CVERecord?id=CVE-2021-41376 Référence CVE CVE-2021-42277 https://www.cve.org/CVERecord?id=CVE-2021-42277 Référence CVE CVE-2021-42292 https://www.cve.org/CVERecord?id=CVE-2021-42292 Référence CVE CVE-2021-42296 https://www.cve.org/CVERecord?id=CVE-2021-42296 Référence CVE CVE-2021-42298 https://www.cve.org/CVERecord?id=

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
1.0.0.0 < 1.11.8091.10468; 1.0.0.0 < 1.12.7977.29537
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 10 Nov 2021 · Last source change 19 Aug 2026, 16:27 UTC · CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2021-28400
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceNIST NVD
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →
  1. Vendor guidanceAuthoritative vendor guidance changed from authoritative remediation link · patch to authoritative remediation link · patch.
    Before
    authoritative remediation link · patch
    After
    authoritative remediation link · patch
    af854a3a-2127-422b-91ae-364da2661108 ↗
  2. Vendor guidanceAuthoritative vendor guidance changed from authoritative remediation link · patch to authoritative remediation link · patch.
    Before
    authoritative remediation link · patch
    After
    authoritative remediation link · patch
    f38d906d-7342-40ea-92c1-6c4a2c6478c8 ↗
  3. Affected versionsThe structured affected or fixed version information changed.
    Before
    1.0.0.0 < 15.0.1106.457; 1.0.0.0 < 15.0.1107.165 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    1.0.0.0 < 1.11.8091.10468; 1.0.0.0 < 1.12.7977.29537 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2021-28400↗Patch or update reference↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2021-41372 · cve.blacktree.nl