Medium severity · published Nov 1, 2023
CVE-2023-20256
Multiple vulnerabilities in the per-user-override feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an…
5.8
CVSS
0.6%
EPSS
No
On KEV
Description
Multiple vulnerabilities in the per-user-override feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass a configured access control list (ACL) and allow traffic that should be denied to flow through an affected device. These vulnerabilities are due to a logic error that could occur when the affected software constructs and applies per-user-override rules. An attacker could exploit these vulnerabilities by connecting to a network through an affected device that has a vulnerable configuration. A successful exploit could allow the attacker to bypass the interface ACL and access resources that would should be protected.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 47% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AS
Adaptive Security Appliance Software · Cisco
9.8.4.22; 9.8.4.25; 9.8.4.26; 9.8.4.29; 9.8.4.32; 9.8.4.33; +34 more · source: NVD
SF
Secure Firewall Threat Defense · Cisco
6.2.3.16; 6.2.3.17; 6.2.3.18; 6.4.0.10; 6.4.0.11; 6.4.0.12; +34 more · source: NVD
Affected product
AS
Adaptive Security Appliance Software
Cisco
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-20256
CVE.org
https://www.cve.org/CVERecord?id=CVE-2023-20256
Vendor Advisory
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ac-acl-bypass-bwd7q6Gb
More from Adaptive Security Appliance Software
9.9
CVE-2025-20333
Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability
9.1
CVE-2023-20269
Cisco Adaptive Security Appliance and Firepower Threat Defense Unauthorized Access Vulnerability
8.8
CVE-2016-6366
Cisco Adaptive Security Appliance (ASA) SNMP Buffer Overflow Vulnerability
8.6
CVE-2026-20349
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software Remote Access SSL VPN Denial of Service Vulnerability
8.6
CVE-2025-20362
Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Missing Authorization Vulnerability
