How severe is CVE-2016-20013?

CVE-2016-20013 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2016-20013 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-20013?

CVE-2016-20013 primarily affects Sha256crypt Project Sha256crypt. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-20013?

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-2016-20013 published?

CVE-2016-20013 was published on 2022-02-19 and last updated on 2026-06-17.

CVE-2016-20013

CVE-2016-20013 is a high-severity vulnerability in Sha256crypt Project Sha256crypt with a CVSS 3.x base score of 7.5. 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-770.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (80th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-770
Affected product: Sha256crypt Project Sha256crypt
Published: 2022-02-19
Last modified: 2026-06-17

Description

sha256crypt and sha512crypt through 0.6 allow attackers to cause a denial of service (CPU consumption) because the algorithm's runtime is proportional to the square of the length of the password.

Frequently asked questions

What is CVE-2016-20013?: sha256crypt and sha512crypt through 0.6 allow attackers to cause a denial of service (CPU consumption) because the algorithm's runtime is proportional to the square of the length of the password.
How severe is CVE-2016-20013?: CVE-2016-20013 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2016-20013 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (80th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-20013?: CVE-2016-20013 primarily affects Sha256crypt Project Sha256crypt. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-20013?: 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-2016-20013 published?: CVE-2016-20013 was published on 2022-02-19 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:sha256crypt_project:sha256crypt:*:*:*:*:*:*:*:*
cpe:2.3:a:sha512crypt_project:sha512crypt:*:*:*:*:*:*:*:*

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