Arbitrary code execution via Unicode SEH overwrite
Published Feb 5, 2026 · Updated Feb 5, 2026
Stack-based buffer overflow in Free Desktop Clock 3.0 allows local users to execute arbitrary code through a crafted Time Zones display name. The Time Zones dialog processes an oversized Unicode display name without a length bound, overwriting nSEH after 457 bytes and redirecting SEH through an unprotected executable module. Exploitation requires a user to open the dialog and paste the crafted text; the published x86 exploit launches code in the user's application context.
Summary
What happened
Stack-based buffer overflow in Free Desktop Clock 3.0 allows local users to execute arbitrary code through a crafted Time Zones display name. The Time Zones dialog processes an oversized Unicode display name without a length bound, overwriting nSEH after 457 bytes and redirecting SEH through an unprotected executable module. Exploitation requires a user to open the dialog and paste the crafted text; the published x86 exploit launches code in the user's application context.
The record
- CVE
- CVE-2020-37126
- Published
- Feb 5, 2026
- Updated
- Feb 5, 2026
- Vendor
- Drive Software Company
- Product
- Free Desktop Clock
- Classifications
- CWE-121, T1203
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 5, 2026CVE publishedPublication date reported by the CVE source.
- Feb 5, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=3.0
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
- Free Desktop Clock x86 Venetian Blinds Zipper 3.0 Unicode Stack Overflowfunctional · demonstrated
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Technologies
Your stack
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Your stack
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