How severe is CVE-2020-37221?

CVE-2020-37221 has a CVSS 3.x base score of 8.4, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-37221 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2020-37221?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2020-37221 have an EU (EUVD) identifier?

Yes. CVE-2020-37221 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-31222.

When was CVE-2020-37221 published?

CVE-2020-37221 was published on 2026-05-13 and last updated on 2026-06-17.

CVE-2020-37221

CVE-2020-37221 is a high-severity vulnerability with a CVSS 3.x base score of 8.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-121.

Key facts

Severity: High (CVSS 3.x base score 8.4)
CVSS v4: 8.6
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2020-31222
Weakness: CWE-121
Published: 2026-05-13
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2020-37221?: 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.
How severe is CVE-2020-37221?: CVE-2020-37221 has a CVSS 3.x base score of 8.4, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-37221 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2020-37221?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2020-37221 have an EU (EUVD) identifier?: Yes. CVE-2020-37221 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-31222.
When was CVE-2020-37221 published?: CVE-2020-37221 was published on 2026-05-13 and last updated on 2026-06-17.

References

Other CWE-121 (Stack-based Buffer Overflow) vulnerabilities

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