CVE-2015-4141 in hostapd
Summary
by MITRE
The WPS UPnP function in hostapd, when using WPS AP, and wpa_supplicant, when using WPS external registrar (ER), 0.7.0 through 2.4 allows remote attackers to cause a denial of service (crash) via a negative chunk length, which triggers an out-of-bounds read or heap-based buffer overflow.
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Analysis
by VulDB Data Team • 05/21/2022
The vulnerability identified as CVE-2015-4141 affects the wireless provisioning service functionality within hostapd and wpa_supplicant implementations that utilize Wi-Fi Protected Setup protocols. This security flaw exists in versions 0.7.0 through 2.4 of these wireless authentication components, specifically when operating in WPS Access Point mode with hostapd or when functioning as WPS External Registrar with wpa_supplicant. The issue manifests through improper input validation mechanisms that fail to adequately sanitize incoming data packets during the Universal Plug and Play communication process.
The technical exploitation of this vulnerability occurs when malicious actors send specially crafted packets containing negative chunk length values to the affected wireless services. This particular input condition triggers memory corruption behaviors within the processing code, resulting in either out-of-bounds read operations or heap-based buffer overflow conditions. The flaw represents a classic example of inadequate input validation and memory management practices that allow attackers to manipulate the normal execution flow of the wireless authentication services. When the system attempts to process these malformed chunk length values, the memory allocation and data handling routines fail, leading to system crashes and complete service disruption.
The operational impact of CVE-2015-4141 extends beyond simple service disruption to encompass potential system stability issues and denial of service conditions that can affect wireless network availability. Networks relying on hostapd or wpa_supplicant for wireless authentication may experience complete service outages when attackers exploit this vulnerability, particularly in environments where wireless access points are critical infrastructure components. The vulnerability affects both enterprise and consumer wireless environments, as it targets fundamental components of wireless authentication protocols that are widely deployed across various network infrastructures. The remote nature of the attack means that adversaries can exploit this flaw from outside the local network perimeter without requiring physical access or elevated privileges within the system.
Security mitigations for this vulnerability involve immediate software updates to versions that contain patched implementations of the WPS UPnP functionality. Organizations should prioritize patch management procedures to ensure all affected wireless authentication components are updated to versions that properly validate chunk length values and implement robust memory management practices. Additionally, network administrators should consider implementing network segmentation and access controls to limit exposure of wireless services to untrusted networks. The vulnerability aligns with CWE-129, which addresses improper validation of array indices, and CWE-125, which covers out-of-bounds read conditions. From an attacker perspective, this vulnerability maps to ATT&CK technique T1499.004, which involves network denial of service attacks, and T1059.007, covering command and scripting interpreters through wireless protocols. Organizations should also implement network monitoring solutions capable of detecting anomalous packet patterns that may indicate exploitation attempts of this specific memory corruption vulnerability.