Improper Handling of Exceptional Conditions in Cisco IOS XE and Cisco IOS - CVE-2022-20920

Vulnerability identifier: #VU67728

CSH Severity: Medium

CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2022-20920

CWE-ID: CWE-755

Exploitation vector: Remote access

Exploit availability: No public exploit available

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

The vulnerability exists due to improper handling of resources during an exceptional situation in the SSH implementation. A remote user can pass specially crafted input to the application and perform a denial of service (DoS) attack.

Cisco IOS XE
Cisco IOS

Install updates from vendor's website.

Cisco IOS XE - addressed in versions Amsterdam-17.3.6, ap-17.3.6.7, ap-17.3.6.76, ap-17.6.3.27, ap-17.6.3.33, ap-17.8.0.121, ap-17.8.0.144, ap-17.9.0.56, ap-17.9.1.8, Bengaluru-17.6.1, Bengaluru-17.6.3, Gibraltar-16.12.6, Cupertino-17.8.1, Cupertino-17.9.1, 008.010(178.017), 15.3(03)JPM, 15.5(01)SY10, 15.8(03)M09, 15.9(03)M06, 16.12(5.73), 16.12.6, 16.12.6a, 16.12.7, 16.12.8, 17.3.5b, 17.3(5.89), 17.3.6, 17.6(0.83), 17.6.1, 17.6.1w, 17.6.1x, 17.6.1y, 17.6.1z, 17.6.1a, 17.6.2, 17.6.3, 17.6.3a, 17.6.4, 17.7.1, 17.7.1a, 17.7.2, 17.8.1, 17.8.1a, 17.9.1, 17.9.1a
Cisco IOS - addressed in versions ap-17.3.6.7, ap-17.3.6.76, ap-17.6.3.27, ap-17.6.3.33, ap-17.8.0.121, ap-17.8.0.144, ap-17.9.0.56, ap-17.9.1.8, 008.010(178.017), 15.3(03)JPM, 15.5(1)SY10, 15.8(03)M09, 15.9(3)M6, 16.12(5.73), 16.12.6, 16.12.6a, 16.12.7, 16.12.8, 17.3.5b, 17.3(5.89), 17.3.6, 17.6(0.83), 17.6.1, 17.6.1w, 17.6.1x, 17.6.1y, 17.6.1z, 17.6.1a, 17.6.2, 17.6.3, 17.6.3a, 17.6.4, 17.7.1, 17.7.1a, 17.7.2, 17.8.1, 17.8.1a, 17.9.1, 17.9.1a

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ssh-excpt-dos-FzOBQTnk

• Denial of service in Cisco IOS and IOS XE Software