CVE-2021-25273Public exploitNetwork attack vector

Administrator-context script execution via unsanitized quarantined email

Published Jul 29, 2021 · Updated Aug 3, 2024

Stored XSS in Sophos UTM before 9.706 allows remote attackers to execute script as an administrator via quarantined email. The quarantine detail view reflects stored, attacker-controlled email subjects, attachment filenames, sender names, and bodies without sufficient sanitization. Exploitation requires a crafted message to enter quarantine and an authenticated administrator to open its details, after which the script runs in the UTM web origin with that session's authority.

CVSS severity4.8
Medium
EPSS probability0.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Sophos UTM before 9.706 allows remote attackers to execute script as an administrator via quarantined email. The quarantine detail view reflects stored, attacker-controlled email subjects, attachment filenames, sender names, and bodies without sufficient sanitization. Exploitation requires a crafted message to enter quarantine and an authenticated administrator to open its details, after which the script runs in the UTM web origin with that session's authority.

The record

CVE
CVE-2021-25273
Published
Jul 29, 2021
Updated
Aug 3, 2024
Vendor
Sophos
Product
Sophos UTM
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 29, 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=unspecified <=9.705

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Sophos · Sophos UTMversion=unspecified <=9.705

Published CVSS scores

3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
4.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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')
T1059.007Command and Scripting Interpreter: JavaScript/JScript

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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