How severe is CVE-2021-29418?

CVE-2021-29418 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-29418 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-29418?

CVE-2021-29418 affects Netmask Project Netmask. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-29418?

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

When was CVE-2021-29418 published?

CVE-2021-29418 was published on 2021-03-30 and last updated on 2026-06-17.

CVE-2021-29418

CVE-2021-29418 is a medium-severity vulnerability in Netmask Project Netmask with a CVSS 3.x base score of 5.3. 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-20.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 2% (74th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Netmask Project Netmask
Published: 2021-03-30
Last modified: 2026-06-17

Description

The netmask package before 2.0.1 for Node.js mishandles certain unexpected characters in an IP address string, such as an octal digit of 9. This (in some situations) allows attackers to bypass access control that is based on IP addresses. NOTE: this issue exists because of an incomplete fix for CVE-2021-28918.

Frequently asked questions

What is CVE-2021-29418?: The netmask package before 2.0.1 for Node.js mishandles certain unexpected characters in an IP address string, such as an octal digit of 9. This (in some situations) allows attackers to bypass access control that is based on IP addresses. NOTE: this issue exists because of an incomplete fix for CVE-2021-28918.
How severe is CVE-2021-29418?: CVE-2021-29418 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-29418 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (74th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-29418?: CVE-2021-29418 affects Netmask Project Netmask. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-29418?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-29418 published?: CVE-2021-29418 was published on 2021-03-30 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:netmask_project:netmask:*:*:*:*:*:node.js:*:*

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