CVE-2020-3702 Overview
CVE-2020-3702 is an information disclosure vulnerability affecting Qualcomm WLAN chipsets used across multiple product lines including Snapdragon Auto, Compute, Connectivity, Consumer IOT, Industrial IOT, Mobile, Voice & Music, Wearables, and Wired Infrastructure and Networking platforms. The vulnerability allows an attacker within adjacent network proximity to cause internal errors in a WLAN device through specifically timed and handcrafted traffic, leading to improper layer 2 Wi-Fi encryption and potential information disclosure over the air.
Critical Impact
Attackers within wireless range can exploit timing-based attacks to bypass Wi-Fi encryption, potentially exposing sensitive network traffic transmitted by affected devices.
Affected Products
- Qualcomm Snapdragon chipsets: APQ8053, IPQ4019, IPQ8064, MSM8909W, MSM8996AU, QCA9531, QCN5502, QCS405, SDX20, SM6150, SM7150
- Debian Linux 9.0 and 10.0
- Arista Access Points: AV2, C-75, C75-E, O-90, O90E, W-68
Discovery Timeline
- September 8, 2020 - CVE-2020-3702 published to NVD
- November 21, 2024 - Last updated in NVD database
Technical Details for CVE-2020-3702
Vulnerability Analysis
This vulnerability stems from improper handling of specifically crafted and precisely timed Wi-Fi traffic that induces internal errors within the WLAN device firmware. When these errors occur, the device fails to properly apply layer 2 Wi-Fi encryption to a discrete set of traffic, resulting in the transmission of potentially sensitive data in an unencrypted or improperly encrypted state over the wireless medium.
The attack requires the attacker to be within adjacent network range (wireless proximity) of the target device. Once in range, no privileges or user interaction are required to exploit the vulnerability. The impact is limited to confidentiality, with no direct effect on integrity or availability of the affected system.
Root Cause
The vulnerability is classified under CWE-319 (Cleartext Transmission of Sensitive Information). The root cause lies in the firmware's failure to maintain proper encryption state when processing malformed or specifically timed wireless frames. This race condition-like behavior causes the encryption layer to temporarily fail, allowing a window during which traffic may be transmitted without proper layer 2 protection.
Attack Vector
The attack vector requires the attacker to be within adjacent network proximity (typically within Wi-Fi range) of the vulnerable device. The attacker crafts and transmits specially timed traffic designed to trigger internal errors in the WLAN device's firmware. This timing attack exploits weaknesses in the encryption state machine, causing the device to transmit certain frames without proper Wi-Fi encryption. An attacker monitoring the wireless medium can then capture and analyze this unencrypted traffic to extract sensitive information.
The attack does not require authentication or any user interaction, making it particularly concerning for IoT devices, access points, and mobile devices deployed in public or semi-public environments where attackers may be within wireless range.
Detection Methods for CVE-2020-3702
Indicators of Compromise
- Unusual patterns of unencrypted or malformed Wi-Fi frames detected by wireless intrusion detection systems
- Anomalous timing patterns in Wi-Fi traffic that deviate from normal communication profiles
- Evidence of traffic capture attempts from unauthorized wireless devices in proximity
- Increased error rates or anomalies in WLAN device firmware logs
Detection Strategies
- Deploy wireless intrusion detection/prevention systems (WIDS/WIPS) to monitor for anomalous Wi-Fi frame patterns
- Implement continuous monitoring of WLAN device firmware logs for internal error conditions
- Conduct regular wireless security assessments to identify unauthorized devices in proximity
- Monitor for firmware update status across all affected Qualcomm-based devices
Monitoring Recommendations
- Enable verbose logging on access points and WLAN infrastructure devices
- Implement network segmentation to limit exposure of sensitive traffic over wireless networks
- Deploy endpoint detection solutions capable of identifying anomalous wireless behavior
- Establish baseline wireless traffic patterns to detect deviations indicative of exploitation attempts
How to Mitigate CVE-2020-3702
Immediate Actions Required
- Identify all devices in your environment using affected Qualcomm chipsets and firmware
- Apply firmware updates from Qualcomm, Arista, or device manufacturers as soon as available
- Review network architecture to minimize sensitive data transmission over potentially affected wireless links
- Consider implementing additional encryption layers (VPN, TLS) for sensitive communications
- Monitor vendor security advisories for updated patches and mitigations
Patch Information
Qualcomm has released security updates addressing this vulnerability as documented in their August 2020 Security Bulletin. Arista has published Security Advisory #11998 with guidance for affected access point products. Debian has issued security advisories DSA-4978 and LTS announcements addressing kernel-level fixes.
Organizations should contact their device manufacturers for specific firmware update availability, as many consumer and IoT devices using these Qualcomm chipsets may require vendor-specific patches.
Workarounds
- Implement VPN or application-layer encryption for all sensitive communications over wireless networks
- Reduce Wi-Fi signal strength where possible to limit the physical range of potential attack
- Isolate affected devices on dedicated network segments with additional monitoring
- Consider temporary wired connections for critical devices until patches can be applied
- Deploy additional network access controls to restrict which devices can communicate with affected systems
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
