CVE-2023-39340 in Connect Secure
Summary
by MITRE • 12/16/2023
A vulnerability exists on all versions of Ivanti Connect Secure below 22.6R2 where an attacker can send a specific request which may lead to Denial of Service (DoS) of the appliance.
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Analysis
by VulDB Data Team • 01/11/2024
The vulnerability identified as CVE-2023-39340 represents a critical denial of service weakness affecting Ivanti Connect Secure appliances across all versions prior to 22.6R2. This flaw resides within the appliance's request processing mechanism and allows remote attackers to potentially disrupt service availability by crafting and sending specific malicious requests to the affected system. The vulnerability demonstrates characteristics consistent with CWE-400, which catalogs weaknesses related to resource exhaustion and improper handling of input data that can lead to system instability and service disruption. The affected appliance operates as a secure access platform that typically manages network connectivity and authentication for remote users, making it a critical component in enterprise security infrastructures where maintaining continuous availability is paramount for business operations.
The technical implementation of this vulnerability involves the appliance's failure to properly validate or handle certain types of incoming requests that trigger an uncontrolled resource consumption pattern or state machine failure within the application layer. Attackers can exploit this weakness by sending specifically crafted requests that cause the system to enter an abnormal processing state, consuming excessive memory, CPU cycles, or other system resources until the appliance becomes unresponsive or crashes entirely. The nature of the flaw suggests it may be related to insufficient input validation or improper error handling within the web application framework that processes user requests. This type of vulnerability aligns with ATT&CK technique T1499.004 which covers network denial of service attacks, and demonstrates how attackers can leverage application-level weaknesses to compromise system availability.
The operational impact of CVE-2023-39340 extends beyond simple service interruption as it can severely disrupt business continuity for organizations relying on Ivanti Connect Secure for remote access management. When an appliance becomes unavailable due to this vulnerability, users lose access to critical network resources and applications, potentially affecting productivity and operational efficiency. The disruption can be particularly severe in environments where the appliance serves as a primary gateway for remote workers, branch office connections, or critical infrastructure access. Organizations may experience cascading effects where dependent systems and services also become unavailable due to the loss of network connectivity through the compromised appliance. This vulnerability can also be leveraged as a preliminary step in more complex attack scenarios where attackers first establish denial of service conditions to create opportunities for further exploitation or to mask other malicious activities within the network.
Mitigation strategies for this vulnerability require immediate implementation of the vendor-provided security patch version 22.6R2 or higher, which addresses the underlying flaw in request processing and input validation. Organizations should also implement network segmentation and access controls to limit exposure of the vulnerable appliance to untrusted networks and users. Monitoring and logging configurations should be enhanced to detect unusual patterns of requests that may indicate exploitation attempts, while network-based intrusion detection systems can be configured to identify and block suspicious traffic patterns associated with the vulnerability. Additionally, implementing rate limiting and request validation mechanisms at network boundaries can provide additional defense-in-depth measures. Organizations should also conduct comprehensive vulnerability assessments to identify any other potentially vulnerable components within their network infrastructure that may be susceptible to similar attack vectors, ensuring that their overall security posture remains resilient against evolving threat landscapes.