CVE-2023-20155 in Firepower Management Center
Summary
by MITRE • 11/01/2023
A vulnerability in a logging API in Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to cause the device to become unresponsive or trigger an unexpected reload. This vulnerability could also allow an attacker with valid user credentials, but not Administrator privileges, to view a system log file that they would not normally have access to. This vulnerability is due to a lack of rate-limiting of requests that are sent to a specific API that is related to an FMC log. An attacker could exploit this vulnerability by sending a high rate of HTTP requests to the API. A successful exploit could allow the attacker to cause a denial of service (DoS) condition due to the FMC CPU spiking to 100 percent utilization or to the device reloading. CPU utilization would return to normal if the attack traffic was stopped before an unexpected reload was triggered.
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Analysis
by VulDB Data Team • 11/29/2023
The vulnerability identified as CVE-2023-20155 represents a critical weakness in Cisco Firepower Management Center software that exposes organizations to both denial of service attacks and potential privilege escalation scenarios. This issue affects the logging API component of the FMC platform, which serves as a central repository for system events and security incidents. The vulnerability stems from insufficient rate-limiting mechanisms within the API endpoint responsible for handling log file requests, creating an exploitable condition that can be leveraged by unauthorized actors to disrupt normal operations. The flaw exists in the software's handling of HTTP requests directed toward the logging interface, where the system fails to implement adequate traffic controls or request throttling measures. This architectural oversight allows malicious actors to flood the API with excessive requests, overwhelming the system resources and potentially causing complete service disruption.
The technical exploitation of this vulnerability follows a straightforward yet effective methodology that aligns with common attack patterns documented in the ATT&CK framework under the T1499 category for network denial of service. Attackers can initiate a high-volume request campaign against the vulnerable API endpoint without requiring authentication, making this particularly dangerous as it can be exploited from any network location. The rate-limiting deficiency creates a window of opportunity where legitimate system operations are disrupted by malicious request flooding, leading to CPU utilization spikes that can reach 100 percent. This excessive resource consumption causes the FMC appliance to become unresponsive or may trigger an unexpected device reload, effectively rendering the security management platform unavailable for legitimate administrative tasks. The vulnerability's impact is compounded by the fact that authenticated users with standard privileges can potentially access system log files that would normally be restricted, representing a privilege escalation vector that could expose sensitive operational data.
Organizations relying on Cisco Firepower Management Center for network security operations face significant operational risks from this vulnerability, particularly in environments where continuous monitoring and threat detection are critical. The denial of service condition created by this flaw can disrupt security operations across the entire network infrastructure, as administrators lose access to crucial log data and management capabilities. The potential for unexpected device reloads creates additional operational challenges, as system uptime becomes unpredictable and security monitoring capabilities may be temporarily unavailable. From a compliance perspective, this vulnerability could impact organizations' ability to maintain audit trails and demonstrate proper security controls, as access to system logs may be restricted or unavailable during attack scenarios. The vulnerability also creates opportunities for attackers to gather intelligence about system operations through unauthorized access to log files, potentially exposing system configurations and security event patterns that could be used in subsequent attacks. This weakness directly impacts the availability and integrity of security operations, making it a critical concern for organizations that depend on continuous network security monitoring and management capabilities.
Mitigation strategies for CVE-2023-20155 should focus on implementing network-level protections combined with software updates and configuration hardening measures. Organizations should deploy network access controls and rate-limiting mechanisms at the perimeter to restrict access to the vulnerable API endpoints, effectively blocking excessive request patterns before they can impact the FMC appliance. The implementation of intrusion prevention systems with signature-based detection capabilities can help identify and block exploitation attempts targeting this specific vulnerability. Cisco has released software updates addressing this issue, and organizations should prioritize applying these patches to eliminate the underlying vulnerability. Network administrators should also implement monitoring solutions that can detect unusual API request patterns and alert security teams to potential exploitation attempts. Configuration hardening measures should include disabling unnecessary API access where possible and implementing strict access controls for privileged system interfaces. The vulnerability aligns with CWE-770, which addresses insufficient resource pooling, and represents a classic example of inadequate input validation and rate-limiting controls that can lead to resource exhaustion attacks. Organizations should also conduct regular security assessments to identify similar weaknesses in other network management systems and ensure comprehensive protection across their entire security infrastructure.