Cyber Resilience

CVE-2024-20450

Memory Safety in Cisco Spa 301 Firmware

Published
07 August 2024
Modified
23 August 2024
Patch / advisory
CVSS Score v3.1 9.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.072 94th percentile
Risk Priority 85 floored blend · peak EPSS

Summary

CVE-2024-20450 is a critical-severity Classic Buffer Overflow (CWE-120) vulnerability in Cisco Spa 301 Firmware. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 6% of CVEs by exploit likelihood; 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-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2024-20450 affects the web-based management interface of Cisco Small Business SPA300 Series and SPA500 Series IP Phones. Multiple buffer overflow conditions exist because the interface does not properly validate incoming HTTP packets for errors. Successful exploitation grants an unauthenticated remote attacker the ability to execute arbitrary commands on the underlying operating system with root privileges.

An attacker can trigger the flaw by sending a single crafted HTTP request to an exposed management interface. No authentication or user interaction is required, and the attack can be performed over the network with low complexity, consistent with the CVSS 9.8 rating.

The Cisco Security Advisory at https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-spa-http-vulns-RJZmX2Xz describes the issues and provides mitigation guidance, including software updates that address the packet-validation errors.

EPSS for the CVE rose from a low baseline after disclosure to a peak of 0.2572 on 2025-12-11 before settling at the current value of 0.2293, indicating increased exploitation interest well after the initial publication date.

EU & UK References

Vulnerability Data

Multiple vulnerabilities in the web-based management interface of Cisco Small Business SPA300 Series IP Phones and Cisco Small Business SPA500 Series IP Phones could allow an unauthenticated, remote attacker to execute arbitrary commands on the underlying operating system with root…

more

privileges. These vulnerabilities exist because incoming HTTP packets are not properly checked for errors, which could result in a buffer overflow. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to overflow an internal buffer and execute arbitrary commands at the root privilege level.

CWE(s)

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.
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.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-20454Same product: Cisco Spa 301 1 Line Ip Phone
CVE-2024-20451Same product: Cisco Spa 301 1 Line Ip Phone
CVE-2023-20162Same vendor: Cisco
CVE-2024-20313Same vendor: Cisco
CVE-2023-20161Same vendor: Cisco
CVE-2023-20157Same vendor: Cisco
CVE-2023-20156Same vendor: Cisco
CVE-2023-20159Same vendor: Cisco
CVE-2025-20333Same vendor: Cisco
CVE-2026-20100Same vendor: Cisco

Affected Assets

cisco
spa 301 firmware
all versions
cisco
spa 303 firmware
all versions
cisco
spa 501g firmware
all versions
cisco
spa 502g firmware
all versions
cisco
spa 504g firmware
all versions
cisco
spa 508g firmware
all versions
cisco
spa 509g firmware
all versions
cisco
spa 512g firmware
all versions
cisco
spa 514g firmware
all versions
cisco
spa 525g firmware
all versions
+1 more product configuration(s) — see NVD for full list

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)
  • V5.2.1

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and analysis can find missing size checks before deployment.

Input validation directly enforces size checks before buffer copies.

Engineering principles require bounds checking and safe buffer handling in design.

Memory protection limits the impact of an overflow once it occurs.

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 development practices directly enforce bounds checking and input validation that prevent classic buffer overflows.

ID.RA-01 partial match
prevents

Vulnerability identification processes such as code review or scanning detect classic buffer overflows before exploitation.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing unchecked buffer copies with corrected versions.

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.

prevents

Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.

finds

Security testing in development and acceptance can detect buffer overflows through fuzzing and static analysis, though it does not prevent them at the source.

prevents

Secure development life cycle mandates processes that can include input validation and bounds checking to prevent buffer overflows.

prevents

Application security requirements can specify input-size validation and safe buffer handling to mitigate classic buffer overflows.

prevents

Secure system architecture and engineering principles promote defensive coding patterns that reduce the likelihood of unchecked buffer copies.

References