CVE-2020-14993

A stack-based buffer overflow on DrayTek Vigor2960, Vigor3900, and Vigor300B devices before 1.5.1...

9.8 Critical

A stack-based buffer overflow on DrayTek Vigor2960, Vigor3900, and Vigor300B devices before 1.5.1.1 allows remote attackers to execute arbitrary code via the formuserphonenumber parameter in an authusersms action to mainfunction.cgi.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

5.54%Up 3.7 points since Apr 14, 2021

What each source reports

NVD Score used 9.8

Record: CVE-2020-14993
CVSS 3.1: 9.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0: 7.5 HighAV:N/AC:L/Au:N/C:P/I:P/A:P
Weakness: CWE-787
Updated: 2026-11-02

CVE List No score

Record: CVE-2020-14993
Updated: 2026-11-02

EUVDEUVD-2020-7123 No score

Record: EUVD-2020-7123
Updated: 2026-11-03

GitHub AdvisoriesGHSA-56hp-cj87-42wh No score

A stack-based buffer overflow on DrayTek Vigor2960, Vigor3900, and Vigor300B devices before 1.5.1...

Record: GHSA-56hp-cj87-42wh
Updated: 2026-11-02

Affected products

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2020-14993 is a critical vulnerability (CVSS 9.8) in Draytek Vigor2960 Firmware, published June 23, 2020. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 5.54%, the 92nd percentile. No source names a fixed version.