SB2021102805 - Multiple DoS vulnerabilities in SSL VPN interface in Cisco Adaptive Security Appliance and Firepower Threat Defense
Published: October 28, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Stack-based buffer overflow (CVE-ID: CVE-2021-1573)
CWE-ID: CWE-121 - Stack-based buffer overflow
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
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)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
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)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
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.