CVE-2020-37221

HIGH

Atomic Alarm Clock 6.3 Stack Overflow via SEH Unicode

Title source: cna
STIX 2.1

Exploitation Summary

EIP tracks 1 public exploit for CVE-2020-37221. PoCs published by boku.

AI-analyzed exploit summary This exploit demonstrates a stack-based buffer overflow in Atomic Alarm Clock 6.3 beta, leveraging Unicode and SEH overwrite to achieve arbitrary code execution. The payload includes a custom decoder and shellcode to launch calc.exe, bypassing bad characters and ASLR.

Description

Atomic Alarm Clock 6.3 contains a stack overflow vulnerability that allows local attackers to execute arbitrary code by supplying a malicious string to the display name textbox in the Time Zones Clock configuration. Attackers can craft a buffer with structured exception handling overwrite and encoded shellcode to bypass SafeSEH protections and execute arbitrary commands with application privileges.

Exploits (1)

exploitdb WORKING POC
by boku · pythonlocalwindows
https://www.exploit-db.com/exploits/48346

This exploit demonstrates a stack-based buffer overflow in Atomic Alarm Clock 6.3 beta, leveraging Unicode and SEH overwrite to achieve arbitrary code execution. The payload includes a custom decoder and shellcode to launch calc.exe, bypassing bad characters and ASLR.

Classification
Working Poc 100%
Attack Type
Rce
Complexity
Moderate
Reliability
Reliable
Target: Atomic Alarm Clock 6.3 beta
No auth needed
Prerequisites: Windows 10 Pro 1909 (x86) · Atomic Alarm Clock 6.3 beta installed · User interaction to paste malicious input into the 'Enter display name' textbox
devstral-2 · analyzed May 13, 2026 Full analysis →

References (2)

Core 2
Core References
Exploit exploit
ExploitDB-48346
https://www.exploit-db.com/exploits/48346
Third Party Advisory third-party-advisory
VulnCheck Advisory: Atomic Alarm Clock 6.3 Stack Overflow via SEH Unicode
https://www.vulncheck.com/advisories/atomic-alarm-clock-stack-overflow-via-seh-unicode

Scores

CVSS v3 8.4
EPSS 0.0015
EPSS Percentile 4.7%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation poc
Automatable no
Technical Impact total

Details

CWE
CWE-121
Status published
Products (1)
Drive-software/Atomic Alarm Clock 6.3
Published May 13, 2026
Tracked Since May 13, 2026