How severe is CVE-2021-23240?

CVE-2021-23240 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-2021-23240 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-23240?

CVE-2021-23240 primarily affects Sudo Project Sudo. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-23240?

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-2021-23240 published?

CVE-2021-23240 was published on 2021-01-12 and last updated on 2026-06-17.

CVE-2021-23240

CVE-2021-23240 is a high-severity vulnerability in Sudo Project Sudo 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-59.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 4.4
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-59
Affected product: Sudo Project Sudo
Published: 2021-01-12
Last modified: 2026-06-17

Description

selinux_edit_copy_tfiles in sudoedit in Sudo before 1.9.5 allows a local unprivileged user to gain file ownership and escalate privileges by replacing a temporary file with a symlink to an arbitrary file target. This affects SELinux RBAC support in permissive mode. Machines without SELinux are not vulnerable.

Frequently asked questions

What is CVE-2021-23240?: selinux_edit_copy_tfiles in sudoedit in Sudo before 1.9.5 allows a local unprivileged user to gain file ownership and escalate privileges by replacing a temporary file with a symlink to an arbitrary file target. This affects SELinux RBAC support in permissive mode. Machines without SELinux are not vulnerable.
How severe is CVE-2021-23240?: CVE-2021-23240 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-2021-23240 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-23240?: CVE-2021-23240 primarily affects Sudo Project Sudo. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-23240?: 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-2021-23240 published?: CVE-2021-23240 was published on 2021-01-12 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:sudo_project:sudo:*:*:*:*:*:*:*:*
cpe:2.3:a:netapp:hci_management_node:-:*:*:*:*:*:*:*
cpe:2.3:a:netapp:solidfire:-:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*

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