How severe is CVE-2020-21528?

CVE-2020-21528 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-21528 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-21528?

CVE-2020-21528 primarily affects Nasm Netwide Assembler. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2020-21528?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-21528 published?

CVE-2020-21528 was published on 2023-08-22 and last updated on 2026-06-17.

CVE-2020-21528

CVE-2020-21528 is a medium-severity vulnerability in Nasm Netwide Assembler with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (37th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Nasm Netwide Assembler
Published: 2023-08-22
Last modified: 2026-06-17

Description

A Segmentation Fault issue discovered in in ieee_segment function in outieee.c in nasm 2.14.03 and 2.15 allows remote attackers to cause a denial of service via crafted assembly file.

Frequently asked questions

What is CVE-2020-21528?: A Segmentation Fault issue discovered in in ieee_segment function in outieee.c in nasm 2.14.03 and 2.15 allows remote attackers to cause a denial of service via crafted assembly file.
How severe is CVE-2020-21528?: CVE-2020-21528 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-21528 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-21528?: CVE-2020-21528 primarily affects Nasm Netwide Assembler. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2020-21528?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-21528 published?: CVE-2020-21528 was published on 2023-08-22 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:nasm:netwide_assembler:2.14.03:rc2:*:*:*:*:*:*
cpe:2.3:a:nasm:netwide_assembler:2.15:*:*:*:*:*:*:*

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