CVE-2017-11090 in Android
Summary
by MITRE
In android for MSM, Firefox OS for MSM, QRD Android, with all Android releases from CAF using the Linux kernel, a buffer overread is observed in __wlan_hdd_cfg80211_set_pmksa when user space application sends PMKID of size less than WLAN_PMKID_LEN bytes.
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Analysis
by VulDB Data Team • 12/07/2019
The vulnerability identified as CVE-2017-11090 represents a critical buffer overread condition affecting multiple Android platforms including MSM variants, Firefox OS for MSM, and QRD Android systems that utilize the Linux kernel. This flaw manifests within the wireless hardware driver subsystem specifically in the __wlan_hdd_cfg80211_set_pmksa function which handles PMKID (Pairwise Master Key Identifier) processing for wireless network authentication. The issue stems from insufficient validation of input parameters where user space applications can submit PMKID values that fall short of the expected WLAN_PMKID_LEN byte requirement, creating a scenario where the kernel processes memory beyond allocated boundaries.
The technical implementation of this vulnerability resides in the wireless driver's handling of IEEE 802.11 authentication protocols where PMKIDs serve as identifiers for cached authentication keys. When a user space application provides a PMKID shorter than the required WLAN_PMKID_LEN bytes, the kernel function fails to properly validate the input length before proceeding with memory operations. This inadequate boundary checking allows the function to read memory locations beyond the intended buffer, potentially accessing uninitialized memory regions, stack data, or other kernel memory areas that could contain sensitive information or allow for arbitrary code execution.
From an operational standpoint, this vulnerability presents significant security implications for wireless network environments as it could enable attackers to exploit the buffer overread condition to gain unauthorized access to kernel memory spaces. The impact extends beyond simple information disclosure since the overread could potentially lead to privilege escalation or system instability. Attackers could craft malicious PMKID values to trigger the vulnerable code path and potentially extract kernel memory contents or manipulate system state through carefully crafted inputs that cause the kernel to access invalid memory addresses.
The vulnerability aligns with CWE-125, which describes "Out-of-bounds Read" conditions where programs access memory locations beyond the boundaries of allocated buffers. Additionally, this issue demonstrates characteristics consistent with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: PowerShell" in the context of kernel-level exploitation, though the actual attack vector involves direct kernel memory manipulation rather than script execution. The affected platforms represent common Android implementations used in mobile devices and embedded systems where wireless connectivity is fundamental, making this vulnerability particularly concerning for widespread impact.
Mitigation strategies for CVE-2017-11090 should focus on implementing proper input validation within the wireless driver subsystem to ensure all PMKID values meet the required length specifications before processing. System administrators should prioritize applying vendor security patches and updates that address the buffer overread condition by adding proper boundary checks and input length validation. The solution requires modifications to the __wlan_hdd_cfg80211_set_pmksa function to explicitly verify that incoming PMKID data matches the expected WLAN_PMKID_LEN before proceeding with memory operations. Organizations should also implement monitoring for abnormal wireless authentication patterns that might indicate exploitation attempts, while maintaining regular security updates to address similar vulnerabilities in wireless subsystems.