CVE-2019-5021

CVE-2019-5021 is a critical-severity vulnerability in Gliderlabs Docker-alpine with a CVSS 3.x base score of 9.8. 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-258.

Key facts

Description

Versions of the Official Alpine Linux Docker images (since v3.3) contain a NULL password for the `root` user. This vulnerability appears to be the result of a regression introduced in December of 2015. Due to the nature of this issue, systems deployed using affected versions of the Alpine Linux container which utilize Linux PAM, or some other mechanism which uses the system shadow file as an authentication database, may accept a NULL password for the `root` user.

Frequently asked questions

What is CVE-2019-5021?
Versions of the Official Alpine Linux Docker images (since v3.3) contain a NULL password for the `root` user. This vulnerability appears to be the result of a regression introduced in December of 2015. Due to the nature of this issue, systems deployed using affected versions of the Alpine Linux container which utilize Linux PAM, or some other mechanism which uses the system shadow file as an authentication database, may accept a NULL password for the `root` user.
How severe is CVE-2019-5021?
CVE-2019-5021 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-5021 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (93rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-5021?
CVE-2019-5021 primarily affects Gliderlabs Docker-alpine. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-5021?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2019-5021 published?
CVE-2019-5021 was published on 2019-05-08 and last updated on 2026-06-17.

References

Affected products (4)

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