How severe is CVE-2021-35978?

CVE-2021-35978 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-2021-35978 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-35978?

CVE-2021-35978 primarily affects Digi Transport Dr64 Firmware. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-35978?

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-2021-35978 published?

CVE-2021-35978 was published on 2021-12-10 and last updated on 2026-06-17.

CVE-2021-35978

CVE-2021-35978 is a critical-severity vulnerability in Digi Transport Dr64 Firmware 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-77.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-77
Affected product: Digi Transport Dr64 Firmware
Published: 2021-12-10
Last modified: 2026-06-17

Description

An issue was discovered in Digi TransPort DR64, SR44 VC74, and WR. The ZING protocol allows arbitrary remote command execution with SUPER privileges. This allows an attacker (with knowledge of the protocol) to execute arbitrary code on the controller including overwriting firmware, adding/removing users, disabling the internal firewall, etc.

Frequently asked questions

What is CVE-2021-35978?: An issue was discovered in Digi TransPort DR64, SR44 VC74, and WR. The ZING protocol allows arbitrary remote command execution with SUPER privileges. This allows an attacker (with knowledge of the protocol) to execute arbitrary code on the controller including overwriting firmware, adding/removing users, disabling the internal firewall, etc.
How severe is CVE-2021-35978?: CVE-2021-35978 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-2021-35978 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-35978?: CVE-2021-35978 primarily affects Digi Transport Dr64 Firmware. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-35978?: 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-2021-35978 published?: CVE-2021-35978 was published on 2021-12-10 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:o:digi:transport_dr64_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:digi:transport_sr44_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:digi:transport_vc74_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:digi:transport_wr11_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:digi:transport_wr11_xt_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:digi:transport_wr21_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:digi:transport_wr31_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:digi:transport_wr41_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:digi:transport_wr44_firmware:*:*:*:*:*:*:*:*

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