Cyber Resilience

CVE-2020-36997

HighPublic PoC

Published: 29 January 2026

Published
29 January 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 0.0037 28.3th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2020-36997 is a high-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Dummysoftware (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 28.3th 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-2020-36997 is a buffer overflow vulnerability (CWE-121) in BacklinkSpeed version 2.4. The flaw occurs during malicious file import, enabling attackers to corrupt the Structured Exception Handler (SEH) chain by overwriting SEH addresses with a specially crafted payload file. This can lead to arbitrary code execution, allowing full control over the affected application. The vulnerability 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.

Remote attackers require no privileges or user interaction to exploit the vulnerability over the network with low complexity. By inducing the application to process a malicious file, they can trigger the buffer overflow, corrupt the SEH chain, and execute arbitrary code, compromising confidentiality, integrity, and availability with high impact.

References include the vendor site at dummysoftware.com and backlinkspeed.html, as well as public proof-of-concept exploits on Exploit-DB (exploit 48726) and a Vulncheck advisory detailing the BacklinkSpeed buffer overflow with SEH overwrite. No specific patches or mitigation steps are detailed in the provided information.

EU & UK References

Vulnerability details

BacklinkSpeed 2.4 contains a buffer overflow vulnerability that allows attackers to corrupt the Structured Exception Handler (SEH) chain through malicious file import. Attackers can craft a specially designed payload file to overwrite SEH addresses, potentially executing arbitrary code and gaining…

more

control of the application.

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?

Buffer overflow with SEH overwrite during remote malicious file processing directly enables unauthenticated RCE over the network (T1190).

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-2020-37159Shared CWE-121
CVE-2024-39603Shared CWE-121
CVE-2024-36258Shared CWE-121
CVE-2024-51138Shared CWE-121
CVE-2025-69763Shared CWE-121

Affected Assets

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

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Validates imported files to prevent buffer overflows from specially crafted payloads that corrupt the SEH chain.

prevent

Implements memory safeguards like ASLR and DEP to block arbitrary code execution from SEH chain overwrites even if overflow occurs.

prevent

Remediates the known buffer overflow flaw through timely patching to eliminate the vulnerability in BacklinkSpeed 2.4.

References