Cyber Resilience

CVE-2023-20187

Cisco Ios Xe 16.10.1 … 3.9.2s

Published
27 September 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 8.6
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
EPSS Score 0.0065 48th percentile
Risk Priority 63 floored blend · peak EPSS

Summary

CVE-2023-20187 is a high-severity Use of Out-of-range Pointer Offset (CWE-823) vulnerability in Cisco Ios Xe. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 48th 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 Multicast Leaf Recycle Elimination (mLRE) feature of Cisco IOS XE Software for Cisco ASR 1000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause the affected device to reload, resulting in a denial…

more

of service (DoS) condition. This vulnerability is due to incorrect handling of certain IPv6 multicast packets when they are fanned out more than seven times on an affected device. An attacker could exploit this vulnerability by sending a specific IPv6 multicast or IPv6 multicast VPN (MVPNv6) packet through the affected device. A successful exploit could allow the attacker to cause a reload of the affected device, resulting in a DoS condition.

CWE(s)
CWE-823NVD-CWE-noinfo

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-20022Same vendor: Cisco
CVE-2025-20202Same product: Cisco Ios Xe
CVE-2025-20155Same product: Cisco Ios Xe
CVE-2024-20313Same product: Cisco Ios Xe
CVE-2024-20306Same product: Cisco Ios Xe
CVE-2026-20270Same product: Cisco Ios Xe
CVE-2024-20307Same product: Cisco Ios Xe
CVE-2025-20169Same product: Cisco Ios Xe
CVE-2025-20175Same product: Cisco Ios Xe
CVE-2025-20174Same product: Cisco Ios Xe

Affected Assets

cisco
ios xe
16.10.1, 16.10.1a, 16.10.1e, 16.10.1s, 16.10.2

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)
  • 2 hardening rules · 2 OS baselines
Validate
Prove the fix (OWASP ASVS)
  • V1.4.1

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 require bounds-checked pointer arithmetic and static analysis to prevent out-of-range offsets.

ID.RA-01 partial match
prevents

SAST/DAST tools used for vulnerability identification can surface this class of coding defect.

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.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect out-of-range pointer offsets before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates input validation and bounds checking that can prevent out-of-range pointer offsets.

A.8.26 Application security requirements partial match
prevents

Application security requirements include memory-safety rules that reduce pointer-offset errors.

A.8.27 Secure system architecture and engineering principles partial match
degrades

Secure architecture principles promote safe pointer handling and memory layout controls.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly forbid unsafe pointer arithmetic and require bounds checks.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Windows 10 (1 rule)
  • V-220726 Data Execution Prevention (DEP) must be configured to at least OptOut. prevents CWE-823

References