CVE-2024-20359
Cisco ASA and FTD Privilege Escalation Vulnerability
Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD)
A vulnerability in a legacy capability that allowed for the preloading of VPN clients and plug-ins and that has been available in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to execute arbitrary code with root-level privileges. Administrator-level privileges are required to exploit this vulnerability. This vulnerability is due to improper validation of a file when it is read from system flash memory. An attacker could exploit this vulnerability by copying a crafted file to the disk0: file system of an affected device. A successful exploit could allow the attacker to execute arbitrary code on the affected device after the next reload of the device, which could alter system behavior. Because the injected code could persist across device reboots, Cisco has raised the Security Impact Rating (SIR) of this advisory from Medium to High.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 24 April 2024. US federal agencies were required to remediate it by 1 May 2024.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 18.8%, which is higher than 97.3% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
Frequently asked questions
Is CVE-2024-20359 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2024-20359.
What does CVE-2024-20359 affect?
CVE-2024-20359 affects Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD). A vulnerability in a legacy capability that allowed for the preloading of VPN clients and plug-ins and that has been available in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to execute arbitrary code with root-level privileges. Administrator-level privileges are required to exploit this vulnerability. This vulnerability is due to improper validation of a file when it is read from system flash memory. An attacker could exploit this vulnerability by copying a crafted file to the disk0: file system of an affected device. A successful exploit could allow the attacker to execute arbitrary code on the affected device after the next reload of the device, which could alter system behavior. Because the injected code could persist across device reboots, Cisco has raised the Security Impact Rating (SIR) of this advisory from Medium to High.
How severe is CVE-2024-20359?
CVE-2024-20359 is rated MEDIUM with a CVSS base score of 6. EPSS puts the probability of exploitation in the next 30 days at 18.8%, higher than 97.3% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 1 May 2024.
How should organisations respond to CVE-2024-20359?
Apply the vendor patch for Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD) as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.