CVE-2024-20439Known exploitationNetwork attack vector

Unauthenticated API administration via static credential

Published Sep 4, 2024 · Updated Oct 21, 2025

Authentication bypass in Cisco Smart Licensing Utility 2.0.0 through 2.2.0 allows remote attackers to access its API as administrators. The running application accepts an undocumented static credential for an administrative account instead of requiring a unique authorized credential. CSLU must have been manually started and remain actively running; successful login grants administrative control over the application API.

CVSS severity9.8
Critical
EPSS probability97.09%
Next 30 days · Nov 1, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Cisco Smart Licensing Utility 2.0.0 through 2.2.0 allows remote attackers to access its API as administrators. The running application accepts an undocumented static credential for an administrative account instead of requiring a unique authorized credential. CSLU must have been manually started and remain actively running; successful login grants administrative control over the application API.

The record

CVE
CVE-2024-20439
Published
Sep 4, 2024
Updated
Oct 21, 2025
Vendor
Clam AntiVirus
Product
Cisco Smart Licensing Utility
Classifications
CWE-912, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 4, 2024CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 2025Record 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=2.0.0
  2. Affected versionversion=2.1.0
  3. Affected versionversion=2.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Clam AntiVirus · Cisco Smart Licensing Utilityversion=2.0.0; version=2.1.0; version=2.2.0

Published CVSS scores

9.8CiscoCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsShadowserver observations through Sep 28, 2026. Gaps indicate unavailable data.
Sep 22, 2026Sep 28, 2026
View daily counts
Reporting dayUnique IPs
Sep 22, 20265
Sep 23, 20261
Sep 24, 2026Unavailable
Sep 25, 20263
Sep 26, 20261
Sep 27, 20264
Sep 28, 20262
Latest reporting daySep 28, 2026
Latest daily unique IPs2
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-912Hidden Functionality
T1078Valid Accounts

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.

Reported exploitation

Technologies

Your stack

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Your stack

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