How severe is CVE-2021-3429?

CVE-2021-3429 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-3429 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3429?

CVE-2021-3429 affects Canonical Cloud-init. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-3429?

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

When was CVE-2021-3429 published?

CVE-2021-3429 was published on 2023-04-19 and last updated on 2026-06-17.

CVE-2021-3429

CVE-2021-3429 is a medium-severity vulnerability in Canonical Cloud-init 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. The underlying weakness is classified as CWE-532.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
EPSS exploit prediction: 0% (12th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-532
Affected product: Canonical Cloud-init
Published: 2023-04-19
Last modified: 2026-06-17

Description

When instructing cloud-init to set a random password for a new user account, versions before 21.2 would write that password to the world-readable log file /var/log/cloud-init-output.log. This could allow a local user to log in as another user.

Frequently asked questions

What is CVE-2021-3429?: When instructing cloud-init to set a random password for a new user account, versions before 21.2 would write that password to the world-readable log file /var/log/cloud-init-output.log. This could allow a local user to log in as another user.
How severe is CVE-2021-3429?: CVE-2021-3429 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-3429 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (12th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3429?: CVE-2021-3429 affects Canonical Cloud-init. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-3429?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-3429 published?: CVE-2021-3429 was published on 2023-04-19 and last updated on 2026-06-17.

References

https://github.com/canonical/cloud-init/commit/b794d426b9ab43ea9d6371477466070d86e10668

Affected products (1)

cpe:2.3:a:canonical:cloud-init:*:*:*:*:*:*:*:*

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