Security Resilience

CVE-2024-20480

Cisco Ios Xe 16.1.1 … 17.9.5b

Published
25 September 2024
Modified
03 October 2024
Patch / 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 0.0057 46th percentile
Risk Priority 65 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-2024-20480 is a high-severity Operator Precedence Logic Error (CWE-783) vulnerability in Cisco Ios Xe. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked at the 46th 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 SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A vulnerability in the DHCP Snooping feature of Cisco IOS XE Software on Software-Defined Access (SD-Access) fabric edge nodes could allow an unauthenticated, remote attacker to cause high CPU utilization on an affected device, resulting in a denial of service…

more

(DoS) condition that requires a manual reload to recover. This vulnerability is due to improper handling of IPv4 DHCP packets. An attacker could exploit this vulnerability by sending certain IPv4 DHCP packets to an affected device. A successful exploit could allow the attacker to cause the device to exhaust CPU resources and stop processing traffic, resulting in a DoS condition that requires a manual reload to recover.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.001 Junk Data Command And Control
Adversaries may add junk data to protocols used for command and control to make detection more difficult.
T1001.002 Steganography Command And Control
Adversaries may use steganographic techniques to hide command and control traffic to make detection efforts more difficult.
T1007 System Service Discovery Discovery
Adversaries may try to gather information about registered local system services.
T1011.001 Exfiltration Over Bluetooth Exfiltration
Adversaries may attempt to exfiltrate data over Bluetooth rather than the command and control channel.
T1014 Rootkit Stealth
Adversaries may use rootkits to hide the presence of programs, files, network connections, services, drivers, and other system components.
T1020 Automated Exfiltration Exfiltration
Adversaries may exfiltrate data, such as sensitive documents, through the use of automated processing after being gathered during Collection.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-20314Same product: Cisco Ios Xe
CVE-2026-20004Same product: Cisco Ios Xe
CVE-2024-20309Same product: Cisco Ios Xe
CVE-2026-20124Same product: Cisco Ios Xe
CVE-2026-20104Same product: Cisco Ios Xe
CVE-2024-20316Same product: Cisco Ios Xe
CVE-2024-20437Same product: Cisco Ios Xe
CVE-2025-20195Same product: Cisco Ios Xe
CVE-2025-20214Same product: Cisco Ios Xe
CVE-2025-20312Same product: Cisco Ios Xe

Affected Assets

cisco
ios xe
16.1.1, 16.1.2, 16.1.3, 16.10.1, 16.10.1a

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and static analysis directly find incorrect evaluation results caused by precedence mistakes.

Documented development standards and coding rules can require constructs that eliminate ambiguous operator precedence.

Engineering principles can mandate explicit parentheses and precedence rules that structurally prevent the logic error from being written.

Flaw identification and remediation processes can locate and correct control-flow errors once they manifest as incorrect runtime behavior.

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 partial match
blocks

Secure SDLC practices (reviews, static analysis, testing) directly catch precedence errors while the control also addresses many other development risks.

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.

blocks

A.8.25 mandates secure SDLC practices including secure coding guidelines, developer training, security checkpoints, and testing that reach operator precedence logic errors, but leaves a bounded remainder where implementation is incomplete or the specific defect slips through reviews and scans.

prevents

Secure coding standards and guidelines directly address operator precedence mistakes.

finds

Security testing can detect logic errors caused by precedence issues.

Hardening callouts derived

DISA STIG baselines are authored against specific weaknesses. Where this CVE cites a broad weakness class, the mapping is not asserted at that abstraction (owner ruling, 2026-09-25: grade only at Base and below), so no rule is shown here rather than a rule shown against the wrong grain.

  • No fine-grained STIG row for CWE-670, a class-level weakness, and none of its children carries one either.

References