CVE-2021-20124
A local file inclusion vulnerability exists in Draytek VigorConnect 1.6.0-B3 in the file download functionality of the WebServlet endpoint. An unauthenticated attacker could leverage this vulnerability to download arbitrary files from the underlying operating system with root privileges.
do firstApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Can a WAF block it? Yes. Path traversal sends `../` sequences in the request, which WAF rules catch, including the common encodings.
Also consider: canonical path validation
Based on the weakness type only; no CVE-specific evidence yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Is CVE-2021-20124 being exploited?
Yes. CVE-2021-20124 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2021-20124?
CVE-2021-20124 is rated High with a CVSS score of 7.5. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2021-20124?
Not known from our data. No patch reference has been recorded for CVE-2021-20124, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2021-20124 affect?
CVE-2021-20124 affects draytek:vigorconnect. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
- affected1.6.0-B3
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
public exploits
Detection templates only, no public exploit found: 1 Nuclei template
- Draytek VigorConnect 6.0-B3 - Local File Inclusion · detection template · high
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
cisa ssvc
- exploitation
- active
- automatable
- yes
- technical impact
- partial
Assessed by CISA 3 Sept 2024 (SSVC 2.0.3).
timeline
- 13 Oct 2021Published
- 3 Sept 2024Added to CISA KEV (exploited in the wild) · 1,055 days (about 3 years) later
- 3 Sept 2024CISA SSVC assessment: exploitation active · 1 day later
- 24 Sept 2024CISA remediation due date (US federal agencies) · 20 days later
- 21 Oct 2025CVE record last updated · 393 days (about 1 year) later
- 2 Nov 2026Analysed by vulneraibility.com · 377 days (about 1 year) later
- Linktenable.com /security/research/tra-2021-42
- Linkcisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-20124
sources
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- Nuclei templates: detection templates
- Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.