Security Resilience

CVE-2024-20303

Cisco Ios Xe 17.10.1 … 17.9.3a

Published
27 March 2024
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v3.1 7.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS Score 0.0032 24th percentile
Risk Priority 53 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2024-20303 is a high-severity Incomplete Cleanup (CWE-459) vulnerability in Cisco Ios Xe. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Protocol or Service Impersonation (T1001.003); ranked at the 24th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-14 (Non-persistence) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A vulnerability in the multicast DNS (mDNS) gateway feature of Cisco IOS XE Software for Wireless LAN Controllers (WLCs) could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper management…

more

of mDNS client entries. An attacker could exploit this vulnerability by connecting to the wireless network and sending a continuous stream of specific mDNS packets. A successful exploit could allow the attacker to cause the wireless controller to have high CPU utilization, which could lead to access points (APs) losing their connection to the controller and result in a DoS condition.

CWE(s)
CWE-459

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.003 Protocol or Service Impersonation Command And Control
Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts.
attack.mitre.org →
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
attack.mitre.org →
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
T1010 Application Window Discovery Discovery
Adversaries may attempt to get a listing of open application windows.
attack.mitre.org →
T1016 System Network Configuration Discovery Discovery
Adversaries may look for details about the network configuration and settings, such as IP and/or MAC addresses, of systems they access or through information discovery of remote systems.
attack.mitre.org →
T1016.001 Internet Connection Discovery Discovery
Adversaries may check for Internet connectivity on compromised systems.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-20140Same product: Cisco Catalyst 9105Axi
CVE-2025-20190Same product: Cisco Catalyst 9105Axi
CVE-2023-41835Shared CWE-459
CVE-2025-29934Shared CWE-459
CVE-2024-26803Shared CWE-459
CVE-2025-38177Shared CWE-459
CVE-2024-47693Shared CWE-459
CVE-2024-26832Shared CWE-459
CVE-2026-108982Shared CWE-459
CVE-2026-43395Shared CWE-459

Affected Assets

cisco
ios xe
17.10.1, 17.10.1a, 17.10.1b, 17.11.1, 17.11.1a

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V6.4.1

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover incomplete cleanup through dynamic analysis or resource-leak testing.

SI-14 Non-persistence good match

Non-persistence mechanisms explicitly initiate resources in a known state and terminate them, directly enforcing cleanup.

AC-12 Session Termination partial match

Session termination forces explicit release of session-related temporary resources.

SC-4 Information in Shared System Resources partial match

Preventing unintended information transfer through shared resources requires complete cleanup of those resources.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.AM-08 partial match
blocks

Life-cycle management encompasses disposal of temporary resources but does not specifically target runtime cleanup bugs.

PR.DS-10 partial match
blocks

Explicitly calls for removing sensitive data after use, directly addressing one class of incomplete cleanup.

PR.PS-06 partial match
blocks

Secure-development practices and coding standards normally require proper resource release and cleanup.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References