Cyber Resilience

CVE-2024-20276

Cisco Ios 15.5\(1\)sy10 … 15.5\(1\)sy9

Published
27 March 2024
Modified
17 June 2026
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 0.0029 21th percentile
Risk Priority 53 floored blend · peak EPSS

Summary

CVE-2024-20276 is a high-severity Uncaught Exception (CWE-248) vulnerability in Cisco Ios. 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 21th 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-8 (Security and Privacy Engineering Principles) and SC-24 (Fail in Known State) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

A vulnerability in Cisco IOS Software for Cisco Catalyst 6000 Series Switches could allow an unauthenticated, adjacent attacker to cause an affected device to reload unexpectedly. This vulnerability is due to improper handling of process-switched traffic. An attacker could exploit…

more

this vulnerability by sending crafted traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition.

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.
T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-20173Same product: Cisco Ios
CVE-2025-20176Same product: Cisco Ios
CVE-2025-20171Same product: Cisco Ios
CVE-2025-20172Same product: Cisco Ios
CVE-2023-20086Same vendor: Cisco
CVE-2024-20312Same product: Cisco Ios
CVE-2024-20311Same product: Cisco Ios
CVE-2025-20198Same vendor: Cisco
CVE-2024-20353Same vendor: Cisco
CVE-2023-20083Same vendor: Cisco

Affected Assets

cisco
ios
15.5\(1\)sy10, 15.5\(1\)sy11, 15.5\(1\)sy5, 15.5\(1\)sy6, 15.5\(1\)sy7

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Security engineering principles include robust exception management to keep the system in a defined state.

Fail-in-known-state reduces the impact when an uncaught exception occurs by preserving a safe condition.

Error handling requirements force structured catching and response to exceptions instead of allowing them to propagate uncaught.

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 explicitly require structured exception handling to prevent uncaught exceptions from reaching production.

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 can detect uncaught exceptions before production deployment.

prevents

Secure development lifecycle includes exception-handling standards that reduce uncaught exceptions.

prevents

Application security requirements typically mandate robust error and exception handling.

prevents

Secure architecture principles call for centralized, comprehensive exception management.

prevents

Secure coding standards directly require catching and handling exceptions to prevent crashes or leaks.

References