Severity: Unknown
Description: An exploitable denial-of-service vulnerability exists in the 802.11w security state handling for hostapd 2.6 connected clients with valid 802.11w sessions. By simulating an incomplete new association, an attacker can trigger a deauthentication against stations using 802.11w, resulting in a denial of service.
CVSS Score: N/A
D
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1. Risk Assessment
The vulnerability CVE-2019-5062 is a denial-of-service vulnerability in hostapd version 2.6, specifically in its handling of 802.11w security states. The nature of the vulnerability stems from an improper handling of incomplete association requests, allowing an attacker to trigger deauthentication of clients using 802.11w. The business impact is potentially significant, as a successful attack can disrupt wireless connectivity for users relying on hostapd 2.6. The likelihood of exploitation is moderate, as the attack requires an attacker to be within adjacent network range and doesn't require complex setup. The ease of exploitation is relatively low, as it requires crafting an incomplete association frame, but several tools and methods exist for this. The primary impact is on availability, causing a disruption of wireless services. Confidentiality and integrity are largely unaffected, as the attack primarily focuses on disrupting connectivity rather than stealing or altering data. The CVSS v3.0 base score of 7.4 indicates a High severity vulnerability.
2. Potential Attack Scenarios
An attacker positioned within wireless range of a hostapd 2.6 access point can launch a denial-of-service attack. The attacker crafts an incomplete association request to the access point, specifically targeting clients currently using 802.11w. This incomplete request causes hostapd to incorrectly trigger a deauthentication frame, disconnecting the targeted clients. The attack process involves the attacker using a wireless adapter capable of injecting frames, capturing the initial association, modifying it to be incomplete, and then resending it to the access point. Multiple clients can be targeted, amplifying the disruption. The potential outcome is widespread disruption of wireless connectivity for users relying on 802.11w, impacting productivity and potentially critical business operations if wireless access is vital.
3. Mitigation Recommendations
The primary mitigation for CVE-2019-5062 is to upgrade hostapd to a version that addresses the vulnerability. Versions after 2.6 should include the fix. Patching is the most effective immediate action. Organizations using hostapd 2.6 on Raspberry Pi or other platforms should prioritize updating to the latest stable version. Additionally, consider implementing wireless intrusion detection/prevention systems (WIDS/WIPS) to detect anomalous deauthentication frames, which can indicate an attack in progress. Monitor wireless network performance for unexpected drops in connectivity, which could be a sign of exploitation. Resources for further information and updates are available at the Talos Intelligence report: https://talosintelligence.com/vulnerability_reports/TALOS-2019-0850. Regularly review hostapd update logs and security advisories to stay informed of new vulnerabilities and patches.
4. Executive Summary
CVE-2019-5062 is a high-severity denial-of-service vulnerability affecting hostapd version 2.6. This vulnerability allows an attacker within wireless range to disrupt wireless connectivity for users using 802.11w security. While not a data breach vulnerability, the disruption of wireless service can impact employee productivity and potentially critical business functions. The most effective mitigation is to upgrade to a newer version of hostapd. Prompt patching is crucial to minimize the risk of disruption. Addressing this vulnerability ensures continued reliable wireless access for our users and minimizes potential business impact. The vulnerability is relatively easy to exploit, making timely patching important.