Security Resilience

CVE-2023-21564

XSS in Microsoft Azure Devops Server 2022

XSS
Published
14 February 2023
Modified
19 August 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
EPSS Score 0.0089 58th percentile
Risk Priority 61 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-21564 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Microsoft Azure Devops Server. Its CVSS base score is 7.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Protocol or Service Impersonation (T1001.003); ranked in the top 42% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2023-21564 is a cross-site scripting vulnerability, tracked as CWE-79, that affects Azure DevOps Server. It received a CVSS 3.1 base score of 7.1 reflecting network attack vector, low complexity, low privileges required, and no user interaction, resulting in high confidentiality impact with limited integrity consequences.

An authenticated attacker with low privileges can send specially crafted requests to the server and achieve script execution in other users' sessions, enabling unauthorized access to sensitive data and limited unauthorized changes within the affected Azure DevOps instance.

Microsoft's advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21564 provides official guidance on mitigation, including the application of security updates released for supported versions of Azure DevOps Server.

The associated EPSS score has remained flat at 0.0637 with no material rise after disclosure.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

Azure DevOps Server Cross-Site Scripting Vulnerability

CWE(s)
CWE-79

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.003 Protocol or Service Impersonation Command And Control
Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts.
attack.mitre.org →
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
attack.mitre.org →
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
attack.mitre.org →
T1011 Exfiltration Over Other Network Medium Exfiltration
Adversaries may attempt to exfiltrate data over a different network medium than the command and control channel.
attack.mitre.org →
T1012 Query Registry Discovery
Adversaries may interact with the Windows Registry to gather information about the system, configuration, and installed software.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-21565Same product: Microsoft Azure Devops Server
CVE-2023-36869Same product: Microsoft Azure Devops Server
CVE-2023-21570Same vendor: Microsoft
CVE-2023-36892Same vendor: Microsoft
CVE-2023-32024Same vendor: Microsoft
CVE-2023-36030Same vendor: Microsoft
CVE-2023-36020Same vendor: Microsoft
CVE-2023-35335Same vendor: Microsoft
CVE-2023-21807Same vendor: Microsoft
CVE-2023-38164Same vendor: Microsoft

Affected Assets

microsoft
azure devops server
2022

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.3.2

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

CA-8 Penetration Testing
addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

SI-10 Information Input Validation
addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

SI-15 Information Output Filtering
addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
blocks

Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).

PR.PS-02 partial match
blocks

Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.5.6 Contact with special interest groups partial match
blocks

A.5.6 only promotes membership in groups to improve knowledge, receive alerts, and share information; it performs no action that stops XSS exploitation (or even the underlying neutralization defect) and is a pure dependency for other controls per the owner's labeling rule.

References