SB2021102805 - Multiple DoS vulnerabilities in SSL VPN interface in Cisco Adaptive Security Appliance and Firepower Threat Defense



SB2021102805 - Multiple DoS vulnerabilities in SSL VPN interface in Cisco Adaptive Security Appliance and Firepower Threat Defense

Published: October 28, 2021

Security Bulletin ID SB2021102805
Severity
Medium
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 secuirty vulnerabilities.


1) Stack-based buffer overflow (CVE-ID: CVE-2021-1573)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error when processing HTTP requests. A remote unauthenticated attacker can send a specially crafted HTTP request to exposed SSL VPN web interface, trigger stack-based buffer overflow and perform a denial of service (DoS) attack.


2) Input validation error (CVE-ID: CVE-2021-34704)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input when processing HTTP requests sent to the SSL VPN interface. A remote attacker can send a specially crafted config-request HTTP request and perform a denial of service (DoS) attack.


3) Out-of-bounds write (CVE-ID: CVE-2021-40118)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error when processing HTTP requests in the SSL VPN interface. A remote attacker can create a specially crafted HTTP reuqst, trigger out-of-bounds write and perform a denial of service (DoS) attack.


Remediation

Install update from vendor's website.