How severe is CVE-2021-20515?

CVE-2021-20515 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20515 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20515?

CVE-2021-20515 affects Ibm Informix Dynamic Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20515?

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

When was CVE-2021-20515 published?

CVE-2021-20515 was published on 2021-04-30 and last updated on 2026-06-17.

CVE-2021-20515

CVE-2021-20515 is a medium-severity vulnerability in Ibm Informix Dynamic Server with a CVSS 3.x base score of 6.7. 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-787.

Key facts

Severity: Medium (CVSS 3.x base score 6.7)
CVSS v2: 4.6
EPSS exploit prediction: 0% (24th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Ibm Informix Dynamic Server
Published: 2021-04-30
Last modified: 2026-06-17

Description

IBM Informix Dynamic Server 14.10 is vulnerable to a stack based buffer overflow, caused by improper bounds checking. A local privileged user could overflow a buffer and execute arbitrary code on the system or cause a denial of service condition. IBM X-Force ID: 198366.

Frequently asked questions

What is CVE-2021-20515?: IBM Informix Dynamic Server 14.10 is vulnerable to a stack based buffer overflow, caused by improper bounds checking. A local privileged user could overflow a buffer and execute arbitrary code on the system or cause a denial of service condition. IBM X-Force ID: 198366.
How severe is CVE-2021-20515?: CVE-2021-20515 has a CVSS 3.x base score of 6.7, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20515 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20515?: CVE-2021-20515 affects Ibm Informix Dynamic Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20515?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20515 published?: CVE-2021-20515 was published on 2021-04-30 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:ibm:informix_dynamic_server:14.10:*:*:*:*:*:*:*

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