CVE-2018-5835 in Android
Summary
by MITRE
If the seq_len is greater then CSR_MAX_RSC_LEN, a buffer overflow in __wlan_hdd_cfg80211_add_key() may occur when copying keyRSC in Android releases from CAF using the linux kernel (Android for MSM, Firefox OS for MSM, QRD Android) before security patch level 2018-06-05.
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Analysis
by VulDB Data Team • 04/05/2023
The vulnerability identified as CVE-2018-5835 represents a critical buffer overflow condition affecting Android-based systems that utilize Qualcomm's Connectivity Architecture Framework. This flaw exists within the wireless driver implementation specifically in the __wlan_hdd_cfg80211_add_key() function, which handles the addition of encryption keys to wireless network connections. The vulnerability manifests when processing sequence numbers that exceed the predefined CSR_MAX_RSC_LEN constant, creating a scenario where memory corruption can occur during key management operations. The affected platforms include Android for MSM, Firefox OS for MSM, and QRD Android releases, making this a widespread issue across multiple mobile operating systems that rely on Qualcomm's wireless chipsets.
The technical root cause of this vulnerability stems from inadequate input validation within the wireless configuration management subsystem. When the seq_len parameter exceeds the CSR_MAX_RSC_LEN threshold, the code attempts to copy keyRSC data without proper bounds checking, resulting in a classic buffer overflow condition. This type of flaw falls under CWE-121, which describes stack-based buffer overflow conditions, and more specifically aligns with CWE-787, representing out-of-bounds write operations. The vulnerability operates at the kernel level within the Linux kernel framework used by these Android variants, making it particularly dangerous as it can potentially be exploited to execute arbitrary code with kernel privileges. The flaw represents a direct violation of memory safety principles and demonstrates poor input validation practices in the wireless subsystem implementation.
The operational impact of this vulnerability extends beyond simple memory corruption, as it creates potential pathways for privilege escalation and system compromise. Attackers could potentially leverage this buffer overflow to execute malicious code within the kernel context, thereby gaining full control over the affected device. The vulnerability affects wireless security features that are fundamental to mobile device operations, particularly those involving WPA/WPA2 encryption management. Given that this flaw exists in wireless drivers used across multiple device manufacturers and operating system variants, the potential attack surface is substantial. The vulnerability's exploitation could lead to complete device compromise, data theft, or the installation of persistent backdoors. According to ATT&CK framework category T1068, this vulnerability could be used for local privilege escalation, while T1547.001 relates to the potential for establishing persistent access through kernel-level modifications.
Mitigation strategies for CVE-2018-5835 require immediate implementation of security patches from the affected vendors, specifically targeting the Android for MSM, Firefox OS for MSM, and QRD Android platforms. Device manufacturers should prioritize the deployment of security updates that address the buffer overflow in the wireless driver subsystem, ensuring that the seq_len parameter validation is properly enforced. System administrators should implement network monitoring to detect anomalous wireless behavior that might indicate exploitation attempts. Additionally, organizations should consider implementing network segmentation and access controls to limit the potential impact of successful exploitation. The patching process should include thorough regression testing to ensure that wireless functionality remains intact while addressing the memory corruption issue. Security teams should also monitor for any reported exploitation attempts and maintain updated threat intelligence feeds related to this specific vulnerability. The fix should involve proper bounds checking mechanisms and input validation to prevent the overflow condition from occurring when sequence numbers exceed the defined maximum length limits.