CVE-2019-15276 in Wireless LAN Controller Software
Summary
by MITRE
A vulnerability in the web interface of Cisco Wireless LAN Controller Software could allow a low-privileged, authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability exists due to a failure of the HTTP parsing engine to handle specially crafted URLs. An attacker could exploit this vulnerability by authenticating with low privileges to an affected controller and submitting the crafted URL to the web interface of the affected device. Conversely, an unauthenticated attacker could exploit this vulnerability by persuading a user of the web interface to click the crafted URL. A successful exploit could allow the attacker to cause an unexpected restart of the device, resulting in a DoS condition.
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Analysis
by VulDB Data Team • 07/13/2024
The vulnerability identified as CVE-2019-15276 resides within the web interface of Cisco Wireless LAN Controller Software, representing a significant security weakness that can be exploited by both authenticated and unauthenticated attackers to disrupt service availability. This flaw specifically affects the HTTP parsing engine component responsible for processing incoming web requests, creating a pathway for malicious actors to manipulate the system through carefully crafted URL inputs. The vulnerability demonstrates a critical design flaw in how the software handles malformed or specially constructed web requests, which can lead to system instability and complete service interruption. The impact extends beyond simple disruption as the vulnerability can be leveraged to force unexpected device restarts, effectively creating a denial of service condition that compromises network connectivity and wireless infrastructure availability.
The technical exploitation of this vulnerability occurs through the manipulation of HTTP parsing mechanisms within the web interface, where the software fails to properly validate or sanitize incoming URL parameters. When a specially crafted URL is processed by the affected HTTP engine, it triggers an unexpected behavior that results in system crash or restart conditions. This type of vulnerability typically falls under CWE-129, which addresses improper validation of input boundaries, and more specifically aligns with CWE-120, concerning buffer overflow conditions that can occur when input data exceeds allocated buffer space. The vulnerability's exploitation requires minimal privileges for authenticated attacks, making it particularly dangerous as it can be leveraged by users with limited access rights to cause significant disruption. The attack vector is particularly concerning because it can be executed through web-based interactions, making it accessible to attackers who might not have direct physical access to the network infrastructure.
From an operational impact perspective, this vulnerability represents a serious threat to wireless network stability and business continuity, as the denial of service condition can affect multiple users and potentially disrupt critical network services. The ability for unauthenticated attackers to exploit this vulnerability through social engineering tactics, such as phishing or malicious links, increases the attack surface significantly and makes the vulnerability more accessible to less technically skilled threat actors. The unexpected restarts caused by exploitation can lead to temporary loss of wireless connectivity for all connected devices, potentially affecting enterprise operations, customer services, and emergency communication systems. Network administrators must consider the cascading effects of such attacks, as wireless infrastructure failures can impact multiple dependent systems and services within an organization's network ecosystem.
Organizations should implement immediate mitigations including applying the latest security patches provided by Cisco, which address the HTTP parsing engine vulnerability through proper input validation and boundary checking mechanisms. Network segmentation and access controls should be enhanced to limit exposure of the affected web interfaces to only necessary personnel, reducing the attack surface for authenticated exploitation attempts. Monitoring solutions should be deployed to detect unusual patterns of web interface access or malformed URL requests that could indicate exploitation attempts. The vulnerability's classification under the MITRE ATT&CK framework places it within the T1499 category for network denial of service attacks, specifically targeting the availability of network services through manipulation of network protocols. Additionally, implementing web application firewalls and HTTP traffic filtering rules can provide additional layers of protection against crafted URL exploitation attempts, while regular security assessments and vulnerability scanning should be conducted to identify similar weaknesses in other network components.