How severe is CVE-2021-20125?

CVE-2021-20125 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-2021-20125 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-2021-20125?

CVE-2021-20125 affects Draytek Vigorconnect. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-20125?

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-2021-20125 published?

CVE-2021-20125 was published on 2021-10-13 and last updated on 2026-06-17.

CVE-2021-20125

CVE-2021-20125 is a critical-severity vulnerability in Draytek Vigorconnect 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-22.

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-22
Affected product: Draytek Vigorconnect
Published: 2021-10-13
Last modified: 2026-06-17

Description

An arbitrary file upload and directory traversal vulnerability exists in the file upload functionality of DownloadFileServlet in Draytek VigorConnect 1.6.0-B3. An unauthenticated attacker could leverage this vulnerability to upload files to any location on the target operating system with root privileges.

Frequently asked questions

What is CVE-2021-20125?: An arbitrary file upload and directory traversal vulnerability exists in the file upload functionality of DownloadFileServlet in Draytek VigorConnect 1.6.0-B3. An unauthenticated attacker could leverage this vulnerability to upload files to any location on the target operating system with root privileges.
How severe is CVE-2021-20125?: CVE-2021-20125 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-2021-20125 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-2021-20125?: CVE-2021-20125 affects Draytek Vigorconnect. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-20125?: 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-2021-20125 published?: CVE-2021-20125 was published on 2021-10-13 and last updated on 2026-06-17.

References

https://www.tenable.com/security/research/tra-2021-42

Affected products (1)

cpe:2.3:a:draytek:vigorconnect:1.6.0:beta3:*:*:*:*:*:*

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