How severe is CVE-2021-27376?

CVE-2021-27376 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-2021-27376 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27376?

CVE-2021-27376 affects Nb-connect Project Nb-connect. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-27376?

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-2021-27376 published?

CVE-2021-27376 was published on 2021-02-18 and last updated on 2026-06-17.

CVE-2021-27376

CVE-2021-27376 is a critical-severity vulnerability in Nb-connect Project Nb-connect 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-119.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 1% (70th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Nb-connect Project Nb-connect
Published: 2021-02-18
Last modified: 2026-06-17

Description

An issue was discovered in the nb-connect crate before 1.0.3 for Rust. It may have invalid memory access for certain versions of the standard library because it relies on a direct cast of std::net::SocketAddrV4 and std::net::SocketAddrV6 data structures.

Frequently asked questions

What is CVE-2021-27376?: An issue was discovered in the nb-connect crate before 1.0.3 for Rust. It may have invalid memory access for certain versions of the standard library because it relies on a direct cast of std::net::SocketAddrV4 and std::net::SocketAddrV6 data structures.
How severe is CVE-2021-27376?: CVE-2021-27376 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-2021-27376 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (70th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27376?: CVE-2021-27376 affects Nb-connect Project Nb-connect. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-27376?: 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-2021-27376 published?: CVE-2021-27376 was published on 2021-02-18 and last updated on 2026-06-17.

References

https://rustsec.org/advisories/RUSTSEC-2021-0021.html

Affected products (1)

cpe:2.3:a:nb-connect_project:nb-connect:*:*:*:*:*:rust:*:*

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