Cyber Resilience

CVE-2023-20089

Cisco Nx-Os 15.2\(1g\) … 16.0\(1j\)

Published
23 February 2023
Modified
21 November 2024
Patch / 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 0.0030 22th percentile
Risk Priority 54 floored blend · peak EPSS

Summary

CVE-2023-20089 is a high-severity Memory Allocation with Excessive Size Value (CWE-789) vulnerability in Cisco Nx-Os. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 22th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

A vulnerability in the Link Layer Discovery Protocol (LLDP) feature for Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) Mode could allow an unauthenticated, adjacent attacker to cause a memory leak, which could result in an unexpected…

more

reload of the device. This vulnerability is due to incorrect error checking when parsing ingress LLDP packets. An attacker could exploit this vulnerability by sending a steady stream of crafted LLDP packets to an affected device. A successful exploit could allow the attacker to cause a memory leak, which could result in a denial of service (DoS) condition when the device unexpectedly reloads. Note: This vulnerability cannot be exploited by transit traffic through the device. The crafted LLDP packet must be targeted to a directly connected interface, and the attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent). In addition, the attack surface for this vulnerability can be reduced by disabling LLDP on interfaces where it is not required.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
T1499.003 Application Exhaustion Flood Impact
Adversaries may target resource intensive features of applications to cause a denial of service (DoS), denying availability to those applications.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-20014Same vendor: Cisco
CVE-2026-20021Same vendor: Cisco
CVE-2026-20013Same vendor: Cisco
CVE-2023-20202Same vendor: Cisco
CVE-2026-20106Same vendor: Cisco
CVE-2026-20015Same vendor: Cisco
CVE-2024-20304Same vendor: Cisco
CVE-2026-20105Same vendor: Cisco
CVE-2025-20140Same vendor: Cisco
CVE-2025-20165Same vendor: Cisco

Affected Assets

cisco
nx-os
15.2\(1g\), 15.2\(2e\), 15.2\(2f\), 15.2\(2g\), 15.2\(2h\)

Mitigating Controls

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.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly prevent coding flaws that trust unvalidated size values for allocations.

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.

finds

Security testing in development can detect and block excessive allocation flaws before deployment.

prevents

Secure development lifecycle includes input validation and size checks that prevent unbounded allocations.

prevents

Application security requirements mandate bounds checking on size parameters to avoid excessive memory allocation.

prevents

Secure architecture principles require resource-limit enforcement that mitigates uncontrolled memory requests.

prevents

Secure coding standards directly prohibit allocating memory from untrusted size values without validation.

finds

Capacity management may detect memory exhaustion symptoms but does not prevent the coding flaw.

References