Local code execution via display-name stack overflow
Published May 13, 2026 · Updated May 13, 2026
Stack-based buffer overflow in Atomic Alarm Clock 6.3 allows local users to execute arbitrary code via a crafted time-zone display name. The Time Zones Clock display-name textbox accepts an oversized Unicode string without an effective length bound, overwriting the stack's SEH record and redirecting control flow to encoded shellcode. Exploitation requires local access to enter the crafted value, and resulting code runs with the Atomic Alarm Clock process privileges.
Summary
What happened
Stack-based buffer overflow in Atomic Alarm Clock 6.3 allows local users to execute arbitrary code via a crafted time-zone display name. The Time Zones Clock display-name textbox accepts an oversized Unicode string without an effective length bound, overwriting the stack's SEH record and redirecting control flow to encoded shellcode. Exploitation requires local access to enter the crafted value, and resulting code runs with the Atomic Alarm Clock process privileges.
The record
- CVE
- CVE-2020-37221
- Published
- May 13, 2026
- Updated
- May 13, 2026
- Vendor
- Drive Software Company
- Product
- Atomic Alarm Clock
- Classifications
- CWE-121, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 13, 2026CVE publishedPublication date reported by the CVE source.
- May 13, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=6.3
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Atomic Alarm Clock 6.3 - Stack Overflow (Unicode+SEH)functional · demonstrated
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Technologies
Your stack
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Your stack
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