CVE-2021-1271Network attack vector

Stored XSS via unvalidated management-interface field

Published Jan 20, 2021 · Updated Nov 12, 2024

Stored XSS in Cisco Secure Web Appliance before 12.5.1 allows remote authenticated users to execute scripts in another user's browser. The web-based management interface accepts malicious data in a specific field without proper validation and stores it for later rendering. The attacker needs high-privilege authenticated access, and another user must view the affected interface; code runs only in that interface's context.

CVSS severity4.8
Medium
EPSS probability0.79%
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 Cisco Secure Web Appliance before 12.5.1 allows remote authenticated users to execute scripts in another user's browser. The web-based management interface accepts malicious data in a specific field without proper validation and stores it for later rendering. The attacker needs high-privilege authenticated access, and another user must view the affected interface; code runs only in that interface's context.

The record

CVE
CVE-2021-1271
Published
Jan 20, 2021
Updated
Nov 12, 2024
Vendor
ClamAV
Product
Cisco Secure Web Appliance
Classifications
CWE-79
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jan 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 12, 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=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

ClamAV · Cisco Secure Web Applianceversion=n/a

Published CVSS scores

4.8CiscoCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N/E:X/RL:X/RC:X

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Public exploit references

No public exploit references are available in this record.

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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