Cyber Resilience

CVE-2020-37159

HighPublic PoC

Published: 07 February 2026

Published
07 February 2026
Modified
15 April 2026
KEV Added
Patch
CVSS Score v4 8.4 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0062 44.8th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2020-37159 is a high-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Softonic (inferred from references). Its CVSS base score is 8.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 44.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).

Deeper analysis

CVE-2020-37159 is a stack-based buffer overflow vulnerability (CWE-121) in Parallaxis Cuckoo Clock 5.0, specifically within the alarm scheduling feature. The flaw allows attackers to execute arbitrary code by crafting a malicious payload exceeding 260 bytes, which overwrites critical memory registers such as EIP and EBP to enable shellcode execution and potential remote code execution. It carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating critical severity.

Unauthenticated remote attackers can exploit this vulnerability over the network with low attack complexity and no user interaction required. Successful exploitation enables full control over the affected system, achieving high impacts on confidentiality, integrity, and availability through arbitrary code execution.

Advisories such as the VulnCheck report detail the buffer overflow mechanics, while Exploit-DB hosts a proof-of-concept exploit (ID 48087) demonstrating the overwrite and shellcode execution. References to the software author PX Company are available via Softonic, but no specific patch or mitigation details are provided in the listed sources.

EU & UK References

Vulnerability details

Parallaxis Cuckoo Clock 5.0 contains a buffer overflow vulnerability that allows attackers to execute arbitrary code by overwriting memory registers in the alarm scheduling feature. Attackers can craft a malicious payload exceeding 260 bytes to overwrite EIP and EBP, enabling…

more

shellcode execution with potential remote code execution.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

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.
Why these techniques?

Direct remote unauthenticated stack buffer overflow enabling arbitrary code execution on a network-accessible application.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-38422Shared CWE-121
CVE-2025-11783Shared CWE-121
CVE-2025-54491Shared CWE-121
CVE-2024-39359Shared CWE-121
CVE-2026-42469Shared CWE-121
CVE-2024-39603Shared CWE-121
CVE-2024-36258Shared CWE-121
CVE-2024-51138Shared CWE-121
CVE-2025-69763Shared CWE-121
CVE-2026-39047Shared CWE-121

Affected Assets

Softonic
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly prevents buffer overflows by validating alarm scheduling inputs to reject payloads exceeding safe lengths like 260 bytes.

prevent

Implements runtime memory protections such as stack canaries, ASLR, and DEP to block exploitation of stack-based overflows overwriting EIP and EBP.

prevent

Mandates timely flaw remediation to patch or replace the vulnerable alarm scheduling feature, eliminating the buffer overflow vulnerability.

References