CVE-2024-20256Network attack vector

Stored script execution via insufficient input validation

Published May 15, 2024 · Updated Aug 15, 2024

Stored XSS in Cisco Secure Email and Web Manager and Secure Web Appliance allows remote authenticated users to execute browser scripts. The web-based management interface retains user-controlled input without sufficient validation and later renders it in another user's browser. Exploitation requires administrative credentials and a user to open a crafted link, exposing browser-based information or actions available in that interface.

CVSS severity4.8
Medium
EPSS probability0.29%
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 Email and Web Manager and Secure Web Appliance allows remote authenticated users to execute browser scripts. The web-based management interface retains user-controlled input without sufficient validation and later renders it in another user's browser. Exploitation requires administrative credentials and a user to open a crafted link, exposing browser-based information or actions available in that interface.

The record

CVE
CVE-2024-20256
Published
May 15, 2024
Updated
Aug 15, 2024
Vendor
ClamAV
Product
Cisco Secure Web Appliance
Classifications
CWE-79, T1189
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. May 15, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=11.7.0-406
  2. Affected versionversion=11.7.0-418
  3. Affected versionversion=11.7.1-006
  4. Affected versionversion=11.7.1-020
  5. Affected versionversion=11.7.1-049
  6. Affected versionversion=11.7.2-011
  7. Affected versionversion=11.8.0-414
  8. Affected versionversion=11.8.1-023
  9. Affected versionversion=11.8.3-018
  10. Affected versionversion=11.8.3-021
  11. Affected versionversion=12.0.1-268
  12. Affected versionversion=12.0.3-007
  13. Affected versionversion=12.5.1-011
  14. Affected versionversion=12.5.2-007
  15. Affected versionversion=12.5.4-005
  16. Affected versionversion=12.5.5-004
  17. Affected versionversion=12.5.6-008
  18. Affected versionversion=14.0.2-012
  19. Affected versionversion=14.0.3-014
  20. Affected versionversion=14.0.4-005
  21. Affected versionversion=14.5.0-498
  22. Affected versionversion=14.5.1-016
  23. Affected versionversion=15.0.0-322

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

ClamAV · Cisco Secure Web Applianceversion=11.7.0-406; version=11.7.0-418; version=11.7.1-006; version=11.7.1-020; version=11.7.1-049; version=11.7.2-011; version=11.8.0-414; version=11.8.1-023; version=11.8.3-018; version=11.8.3-021; version=12.0.1-268; version=12.0.3-007; version=12.5.1-011; version=12.5.2-007; version=12.5.4-005; version=12.5.5-004; version=12.5.6-008; version=14.0.2-012; version=14.0.3-014; version=14.0.4-005; version=14.5.0-498; version=14.5.1-016; version=15.0.0-322
ClamAV · Cisco Secure Email and Web Managerversion=11.0.0-115; version=11.0.1-161; version=11.5.1-105; version=12.0.0-452; version=12.0.1-011; version=12.5.0-636; version=12.5.0-658; version=12.5.0-670; version=12.5.0-678; version=12.8.1-002; version=12.8.1-021; version=13.0.0-277; version=13.6.2-078; version=13.8.1-068; version=13.8.1-074; version=13.8.1-108; version=14.0.0-404; version=14.1.0-223; version=14.1.0-227; version=14.2.0-212; version=14.2.0-224; version=14.2.1-020; version=14.3.0-120; version=15.0.0-334; version=9.0.0-087

Published CVSS scores

4.8CiscoCVSS: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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

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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