# DrayTek VigorConnect: 2 actively exploited vulnerabilities · pwn.watch

> CVE-2021-20123: Draytek VigorConnect contains a path traversal vulnerability in the DownloadFileServlet endpoint. An unauthenticated attacker could leverage this vulnerability to download arbitrary files from the underlying operating system with root privileges. CVE-2021-20124: Draytek VigorConnect contains a path traversal vulnerability 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. Added to the CISA KEV catalog on 2024-09-03. CVE-2021-20123, CVE-2021-20124 were assigned before 2024; the KEV listing came in 2024.

Page: https://pwn.watch/i/draytek-vigorconnect-cve-2021-20123-20124 · generated 2026-10-22T22:00:08.805Z

## Status
- Severity: high · status: closed · patch: patched
- Product: DrayTek VigorConnect
- Started: 2024-09-03 · closed: 2024-09-03
- CVEs: CVE-2021-20123, CVE-2021-20124
- Affected: See vendor advisory (versions are not listed in the KEV record)
- Fixed in: See vendor advisory linked in sources

## Follow this incident
- RSS (one item per update): https://pwn.watch/i/draytek-vigorconnect-cve-2021-20123-20124/feed.xml
- JSON Feed: https://pwn.watch/i/draytek-vigorconnect-cve-2021-20123-20124/feed.json
- Full data (timeline, sources, posts, agentBrief): https://pwn.watch/i/draytek-vigorconnect-cve-2021-20123-20124.json
- This file: https://pwn.watch/i/draytek-vigorconnect-cve-2021-20123-20124/llms.txt

## Updates (newest first)
- 2024-09-03: CISA added CVE-2021-20123 to the KEV catalog (federal deadline 2024-09-24) (https://www.cisa.gov/known-exploited-vulnerabilities-catalog)
- 2024-09-03: CISA added CVE-2021-20124 to the KEV catalog (federal deadline 2024-09-24) (https://www.cisa.gov/known-exploited-vulnerabilities-catalog)

## Fix brief
# Security brief: DrayTek VigorConnect: 2 actively exploited vulnerabilities

Source: https://pwn.watch/i/draytek-vigorconnect-cve-2021-20123-20124 · status: closed (closed Sep 3, 2024) · severity: high · updated Sep 3, 2024

## Patch status
**PATCHED: fixed releases exist. Upgrade to a fixed version.**

## What it is
CVE-2021-20123: Draytek VigorConnect contains a path traversal vulnerability in the DownloadFileServlet endpoint. An unauthenticated attacker could leverage this vulnerability to download arbitrary files from the underlying operating system with root privileges. CVE-2021-20124: Draytek VigorConnect contains a path traversal vulnerability 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. Added to the CISA KEV catalog on 2024-09-03. CVE-2021-20123, CVE-2021-20124 were assigned before 2024; the KEV listing came in 2024.

Severity detail: CVSS 7.5 (v3.1, CISA-ADP), actively exploited (CISA KEV)

- Product: DrayTek VigorConnect
- CVE / advisory ids: CVE-2021-20123, CVE-2021-20124

## Affected versions
- See vendor advisory (versions are not listed in the KEV record)

## Check whether you're affected
No generic command applies (the product is a hosted service, appliance or desktop app). Check the installed version in its admin UI / About screen and compare with the versions above.

## Fix
Upgrade to one of these fixed versions (or later on the same branch):
- See vendor advisory linked in sources

After upgrading, re-run the checks above and redeploy/restart the affected services.

## Latest updates
- Sep 3, 2024: CISA added CVE-2021-20123 to the KEV catalog (federal deadline 2024-09-24)
- Sep 3, 2024: CISA added CVE-2021-20124 to the KEV catalog (federal deadline 2024-09-24)

## Advisories
- [DrayTek advisory: CVE-2021-20123](https://www.draytek.com/about/security-advisory/vigorconnect-software-security-vulnerability-(cve-2021-20123-cve-2021-20129)) (DrayTek)
- [NVD: CVE-2021-20123](https://nvd.nist.gov/vuln/detail/CVE-2021-20123) (NVD)
- [NVD: CVE-2021-20124](https://nvd.nist.gov/vuln/detail/CVE-2021-20124) (NVD)
- [CISA Known Exploited Vulnerabilities Catalog](https://www.cisa.gov/known-exploited-vulnerabilities-catalog) (CISA)

## Caveats
Derived from the CISA KEV JSON feed (catalogVersion 2026.10.21); CVSS from the CVE record (cveawg.mitre.org). startedAt is the CVE publication date when it fell in 2024 before the KEV listing, else the KEV dateAdded; exploitation may have begun earlier. closedAt is the KEV listing date (a fix or mitigation was available then unless noted).

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Machine-readable: https://pwn.watch/i/draytek-vigorconnect-cve-2021-20123-20124.json · all incidents: https://pwn.watch/incidents.json. Verify against the vendor advisory before changing production systems.