CVE-2024-20392Network attack vector

Cross-site scripting via API response splitting

Published May 15, 2024 · Updated Aug 1, 2024

HTTP response splitting in Cisco Secure Email Gateway allows remote attackers to execute browser scripts through a crafted management-API link. The web-based management API accepts insufficiently validated parameter values into an HTTP response, allowing attacker-supplied CRLF sequences to split headers. Exploitation requires a targeted interface user to click the link; successful XSS runs arbitrary script in that user’s browser or exposes sensitive browser-held information.

CVSS severity6.1
Medium
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

HTTP response splitting in Cisco Secure Email Gateway allows remote attackers to execute browser scripts through a crafted management-API link. The web-based management API accepts insufficiently validated parameter values into an HTTP response, allowing attacker-supplied CRLF sequences to split headers. Exploitation requires a targeted interface user to click the link; successful XSS runs arbitrary script in that user’s browser or exposes sensitive browser-held information.

The record

CVE
CVE-2024-20392
Published
May 15, 2024
Updated
Aug 1, 2024
Vendor
ClamAV
Product
Cisco Secure Email
Classifications
CWE-113, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 15, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 1, 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=11.0.3-238
  2. Affected versionversion=11.1.0-069
  3. Affected versionversion=11.1.0-128
  4. Affected versionversion=12.0.0-419
  5. Affected versionversion=12.1.0-071
  6. Affected versionversion=12.1.0-087
  7. Affected versionversion=12.1.0-089
  8. Affected versionversion=12.5.0-066
  9. Affected versionversion=12.5.3-041
  10. Affected versionversion=12.5.4-041
  11. Affected versionversion=13.0.0-392
  12. Affected versionversion=13.0.5-007
  13. Affected versionversion=13.5.1-277
  14. Affected versionversion=13.5.4-038
  15. Affected versionversion=14.0.0-698
  16. Affected versionversion=14.2.0-620
  17. Affected versionversion=14.2.1-020
  18. Affected versionversion=14.3.0-032
  19. Affected versionversion=15.0.0-104
  20. Affected versionversion=15.0.1-030
  21. Affected versionversion=15.5.0-048

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco Secure Emailversion=11.0.3-238; version=11.1.0-069; version=11.1.0-128; version=12.0.0-419; version=12.1.0-071; version=12.1.0-087; version=12.1.0-089; version=12.5.0-066; version=12.5.3-041; version=12.5.4-041; version=13.0.0-392; version=13.0.5-007; version=13.5.1-277; version=13.5.4-038; version=14.0.0-698; version=14.2.0-620; version=14.2.1-020; version=14.3.0-032; version=15.0.0-104; version=15.0.1-030; version=15.5.0-048

Published CVSS scores

6.1Cisco Systems, Inc.CVSS:3.1/AV:N/AC:L/PR:N/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.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-113Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')
T1203Exploitation for Client Execution

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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