CVE-2024-20359: medium-severity vulnerability in Cisco Adaptive Security Appliance (ASA) Software
Published · Updated
68Vexday Risk Score
Prioritize patching. It under exploitation confirmed by CISA and has a public proof of concept.
ssvc Actcvss 6epss 19%
from disclosure to weapon
Published on NVDApr 24
CISA KEVApr 24
exploitation probability
19%top 3% of all CVEs
observed exploitation
yesCISA + VulnCheck
1 public exploit(s)
Action required by CISAfederal deadline: 2024-05-01
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
In short
A flaw in Cisco ASA and FTD software allows an authenticated administrator to inject malicious code into the device's storage. When the device restarts, this code runs with the highest privileges, potentially taking complete control of the firewall.
Technical detail
CWE-94 (improper input validation) in legacy VPN client preloading functionality permits authenticated local attackers with admin credentials to craft a malicious file and write it to disk0:, which executes with root privileges upon device reload. The injected code persists across reboots, enabling persistent compromise of the affected appliance.
Summary generated and translated by AI from the official description.
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.