CVE-2024-20439: Cisco Smart Licensing Utility Static Credential Vulnerability
Cisco · Smart Licensing Utility · NVD published 2024-09-04 · posted 2025-03-31 · last modified 2026-06-17
What it is
A vulnerability in Cisco Smart Licensing Utility (CSLU) could allow an unauthenticated, remote attacker to log into an affected system by using a static administrative credential. This vulnerability is due to an undocumented static user credential for an administrative account. An attacker could exploit this vulnerability by using the static credentials to login to the affected system. A successful exploit could allow the attacker to login to the affected system with administrative rights over the CSLU application API.
| Weakness | CWE-912CWE-798 |
|---|---|
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (source: [email protected]) |
| CISA due date | 2025-04-21 (for US federal agencies under BOD; a good deadline for everyone) |
| ATT&CK tactics | Execution → Credential Access |
Exploitation evidence
First exploit evidence seen: 2025-03-31 (earliest date across the sources below).
Exploited in the wild
- CISA KEV: listed since 2025-03-31. Source
Sources: CISA KEV.
Defend the Chain
The attack chain for CVE-2024-20439 laid across the MITRE ATT&CK Enterprise tactics. Solid cards come from the MITRE CTID KEV mappings; dashed cards are inferred by CVERadar from the CWE or description. Correct defences are real ATT&CK mitigations for that technique.
Pick a red technique card on the board, then choose the defence that stops it.
Defend against T1106 Native API CTID: primary impact
Due to static credentials found in Cisco Smart Licensing Utility, a remote, unauthenticated attacker can gain administrative access through the API.
How to fix it
CISA required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. (source: CISA KEV)
Fixed versions
- cisco smart license utility: upgrade to 2.3.0 or later (affected from 2.0.0)
Derived from the NVD CPE configuration (versionEndExcluding / versionEndIncluding). Always confirm with the vendor advisory.
Vendor advisories and patches
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cslu-7gHMzWmw (CISA KEV notes)
MITRE ATT&CK mitigations for this chain
- M1038 Execution Prevention (for T1106) : Identify and block potentially malicious software executed that may be executed through this technique by using application control tools, like Windows Defender Application Control, AppLocker, or Software Restriction Policies where appropriate.
- M1040 Behavior Prevention on Endpoint (for T1106) : On Windows 10, enable Attack Surface Reduction (ASR) rules to prevent Office VBA macros from calling Win32 APIs.
- M1041 Encrypt Sensitive Information (for T1552) : When possible, store keys on separate cryptographic hardware instead of on the local system.
- M1051 Update Software (for T1552) : Apply patch KB2962486 which prevents credentials from being stored in GPPs.
- M1017 User Training (for T1552) : Ensure that developers and system administrators are aware of the risk associated with having plaintext passwords in software configuration files that may be left on endpoint systems or servers.
- M1015 Active Directory Configuration (for T1552) : Remove vulnerable Group Policy Preferences.
- M1027 Password Policies (for T1552) : Use strong passphrases for private keys to make cracking difficult. Do not store credentials within the Registry. Establish an organizational policy that prohibits password storage in files.
- M1028 Operating System Configuration (for T1552) : There are multiple methods of preventing a user's command history from being flushed to their .bash_history file, including use of the following commands: <code>set +o history</code> and <code>set -o history</code> to start logging again; <code>unset HISTFILE</code> being added to a user's .bash_rc file; and <code>ln -
- M1037 Filter Network Traffic (for T1552) : Limit access to the Instance Metadata API. A properly configured Web Application Firewall (WAF) may help prevent external adversaries from exploiting Server-side Request Forgery (SSRF) attacks that allow access to the Cloud Instance Metadata API.
- M1022 Restrict File and Directory Permissions (for T1552) : Restrict file shares to specific directories with access only to necessary users.
Detection Generic guidance
- Execution: Watch for the service process spawning shells or script interpreters (cmd.exe, powershell, sh, bash, python) via EDR process-tree rules.
- Credential Access: Monitor for credential dumping, unusual LSASS access and sudden authentication from new sources.
Response checklist Generic guidance
- Inventory: find every instance of the affected product and version (include internet-facing and forgotten ones).
- Patch or mitigate per the vendor advisory; if you cannot patch, remove internet exposure or apply the vendor workaround.
- Assume compromise if the system was exposed before patching: hunt for the indicators in the advisory and review logs back to the disclosure date.
- Rotate credentials and secrets stored on or used by the affected system if compromise cannot be ruled out.