How severe is CVE-2021-20264?

CVE-2021-20264 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20264 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20264?

CVE-2021-20264 primarily affects Oracle Openjdk. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20264?

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.

When was CVE-2021-20264 published?

CVE-2021-20264 was published on 2021-10-06 and last updated on 2026-06-17.

CVE-2021-20264

CVE-2021-20264 is a high-severity vulnerability in Oracle Openjdk with a CVSS 3.x base score of 7.8. 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-732.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 4.6
EPSS exploit prediction: 0% (18th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-732
Affected product: Oracle Openjdk
Published: 2021-10-06
Last modified: 2026-06-17

Description

An insecure modification flaw in the /etc/passwd file was found in the openjdk-1.8 and openjdk-11 containers. This flaw allows an attacker with access to the container to modify the /etc/passwd and escalate their privileges. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

Frequently asked questions

What is CVE-2021-20264?: An insecure modification flaw in the /etc/passwd file was found in the openjdk-1.8 and openjdk-11 containers. This flaw allows an attacker with access to the container to modify the /etc/passwd and escalate their privileges. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
How severe is CVE-2021-20264?: CVE-2021-20264 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20264 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20264?: CVE-2021-20264 primarily affects Oracle Openjdk. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20264?: 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.
When was CVE-2021-20264 published?: CVE-2021-20264 was published on 2021-10-06 and last updated on 2026-06-17.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1932283

Affected products (2)

cpe:2.3:a:oracle:openjdk:1.8.0:*:*:*:*:*:*:*
cpe:2.3:a:oracle:openjdk:11:*:*:*:*:*:*:*

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