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.

Published: 2021-12-10 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-35978 is rated High Risk (70.5/100): CVSS Critical severity, with high exploitation likelihood (EPSS 8.07%, 92th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-35978

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 8.94% 8.07% -0.87%
2 2025-11-18 8.07% 8.94% +0.87%
3 2025-03-30 — 8.07% —

Full EPSS history (14 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-35978

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
10.0 2.0 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 10.0 [email protected]

Weakness enumeration for CVE-2021-35978

Affected software / configurations for CVE-2021-35978

Vendor Product Version Raw CPE
digi transport_dr64_firmware <= 5.2.4.9 cpe:2.3:o:digi:transport_dr64_firmware:*:*:*:*:*:*:*:*
digi transport_sr44_firmware — cpe:2.3:o:digi:transport_sr44_firmware:*:*:*:*:*:*:*:*
digi transport_vc74_firmware <= 5.2.4.9 cpe:2.3:o:digi:transport_vc74_firmware:*:*:*:*:*:*:*:*
digi transport_wr11_firmware <= 8.2.1.3 cpe:2.3:o:digi:transport_wr11_firmware:*:*:*:*:*:*:*:*
digi transport_wr11_xt_firmware <= 8.2.1.3 cpe:2.3:o:digi:transport_wr11_xt_firmware:*:*:*:*:*:*:*:*
digi transport_wr21_firmware <= 8.2.1.3 cpe:2.3:o:digi:transport_wr21_firmware:*:*:*:*:*:*:*:*
digi transport_wr31_firmware <= 8.2.1.3 cpe:2.3:o:digi:transport_wr31_firmware:*:*:*:*:*:*:*:*
digi transport_wr41_firmware >= 5.0.0.0, <= 5.2.4.6 cpe:2.3:o:digi:transport_wr41_firmware:*:*:*:*:*:*:*:*
digi transport_wr41_firmware >= 6.0.0.0, <= 6.1.3.5 cpe:2.3:o:digi:transport_wr41_firmware:*:*:*:*:*:*:*:*
digi transport_wr41_firmware >= 8.0.0.0, <= 8.3.1.2 cpe:2.3:o:digi:transport_wr41_firmware:*:*:*:*:*:*:*:*
digi transport_wr44_firmware <= 8.3.1.2 cpe:2.3:o:digi:transport_wr44_firmware:*:*:*:*:*:*:*:*

References for CVE-2021-35978

cvelogic Threat Intelligence