CVE-2021-20123: Draytek VigorConnect Path Traversal Vulnerability

CISA Known Exploited Vulnerability (KEV)

Description

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.

Required action (CISA)

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Notes

https://www.draytek.com/about/security-advisory/vigorconnect-software-security-vulnerability-(cve-2021-20123-cve-2021-20129); https://nvd.nist.gov/vuln/detail/CVE-2021-20123

Weakness behind it

CISA records this vulnerability as an instance of CWE-22. From there the chain continues into CAPEC attack patterns and ATT&CK techniques, all inside this corpus.

References

• NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-20123
• KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog