CVE-2021-28459Public exploitNetwork attack vector

Account compromise via unsanitized process-template name

Published Apr 13, 2021 · Updated Aug 3, 2024

Reflected XSS in Microsoft Azure DevOps Server 2020.0.1 allows attackers to run script through a crafted process-template archive. The process-template upload reads the name from ProcessTemplate.xml inside the ZIP and reflects it into the browser without sanitization. Exploitation requires a privileged user to upload the archive; the injected script then runs in that user's browser and can compromise the account.

CVSS severity6.1
Medium
EPSS probability2.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in Microsoft Azure DevOps Server 2020.0.1 allows attackers to run script through a crafted process-template archive. The process-template upload reads the name from ProcessTemplate.xml inside the ZIP and reflects it into the browser without sanitization. Exploitation requires a privileged user to upload the archive; the injected script then runs in that user's browser and can compromise the account.

The record

CVE
CVE-2021-28459
Published
Apr 13, 2021
Updated
Aug 3, 2024
Vendor
Microsoft
Product
Azure DevOps Server
Classifications
CWE-79, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2020 <publication

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Azure DevOps Serverversion=2020 <publication

Published CVSS scores

6.1Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.002User Execution: Malicious File

Public exploit references

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Technologies

Your stack

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Your stack

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