SB2021100401 - Multiple vulnerabilities in Zyxel ZyWALL VPN2S

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Main Vulnerability Database SB2021100401

SB2021100401 - Multiple vulnerabilities in Zyxel ZyWALL VPN2S

Published: October 4, 2021

Security Bulletin ID SB2021100401
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Path traversal (CVE-ID: CVE-2021-35027)

CWE-ID: CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to perform directory traversal attacks.

The vulnerability exists due to input validation error when processing directory traversal sequences in the web server. A remote attacker can send a specially crafted HTTP request and read arbitrary files on the system.


2) OS Command Injection (CVE-ID: CVE-2021-35028)

CWE-ID: CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local user to execute arbitrary shell commands on the target system.

The vulnerability exists due to improper input validation in the CGI program. A local user can pass specially crafted data to the application and execute arbitrary OS commands on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.


Remediation

Install update from vendor's website.

References