CVE-2023-20120Network attack vector

Browser script execution via insufficient input validation

Published Jun 28, 2023 · Updated Oct 25, 2024

Stored XSS in Cisco Secure Web Appliance AsyncOS allows remote authenticated users to execute scripts in another user's browser. The management interface insufficiently validates submitted input before storing it, but Cisco has not disclosed the affected parameter or storage path. Exploitation requires valid appliance credentials and a user who clicks a crafted link; successful code runs in the interface context and can access sensitive browser data.

CVSS severity5.4
Medium
EPSS probability0.47%
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 AsyncOS allows remote authenticated users to execute scripts in another user's browser. The management interface insufficiently validates submitted input before storing it, but Cisco has not disclosed the affected parameter or storage path. Exploitation requires valid appliance credentials and a user who clicks a crafted link; successful code runs in the interface context and can access sensitive browser data.

The record

CVE
CVE-2023-20120
Published
Jun 28, 2023
Updated
Oct 25, 2024
Vendor
ClamAV
Product
Cisco Secure Web Appliance
Classifications
CWE-79, T1204.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 28, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 25, 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 privilegesauthenticated

What is affected?

ClamAV · Cisco Secure Web Applianceversion=n/a

Published CVSS scores

6.1NISTCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
5.4Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001User Execution: Malicious Link

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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