CVE-2011-1149 in Android
Summary
by MITRE
Android before 2.3 does not properly restrict access to the system property space, which allows local applications to bypass the application sandbox and gain privileges, as demonstrated by psneuter and KillingInTheNameOf, related to the use of Android shared memory (ashmem) and ASHMEM_SET_PROT_MASK.
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Analysis
by VulDB Data Team • 11/05/2021
The vulnerability described in CVE-2011-1149 represents a critical security flaw in Android operating systems prior to version 2.3, specifically targeting the system property space access controls. This issue stems from insufficient restrictions on how local applications can interact with the underlying system memory management mechanisms, creating a pathway for privilege escalation attacks. The vulnerability manifests through improper access control mechanisms that should have prevented unauthorized applications from manipulating system-level properties and memory segments.
The technical implementation of this vulnerability involves the exploitation of Android shared memory (ashmem) functionality combined with the ASHMEM_SET_PROT_MASK ioctl command. This combination allows malicious applications to manipulate memory protection masks and gain unauthorized access to system resources that should remain protected. The flaw specifically affects the kernel-level memory management subsystem where the ashmem driver fails to properly validate access permissions when processing memory protection requests. This vulnerability enables attackers to bypass the standard application sandbox mechanisms that are designed to isolate applications from each other and from system resources.
The operational impact of this vulnerability is significant as it allows local applications to completely circumvent the Android security model and escalate privileges to system-level access. Attackers can leverage this flaw to execute arbitrary code with elevated privileges, potentially gaining access to sensitive system data, modifying critical system files, or establishing persistent backdoors. The psneuter and KillingInTheNameOf exploits demonstrate how this vulnerability can be weaponized to compromise devices running affected Android versions. These exploits specifically target the memory management subsystem to gain unauthorized access to system properties and resources that should remain restricted to system-level processes.
The vulnerability aligns with CWE-284, which addresses improper access control in software systems, and relates to the broader category of privilege escalation flaws that allow unauthorized users to gain elevated system privileges. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and system binary exploitation, specifically targeting the T1068 (Local Privilege Escalation) and T1059 (Command and Scripting Interpreter) tactics. The vulnerability also represents a critical weakness in the Android security model's enforcement of the principle of least privilege, where applications should not be able to access system resources beyond their intended scope.
Mitigation strategies for this vulnerability require immediate system updates to Android 2.3 or later versions where the access control mechanisms have been properly implemented. System administrators should ensure that all affected devices receive the appropriate security patches and that applications are updated to versions that properly enforce memory access controls. Additionally, organizations should implement monitoring solutions that can detect anomalous memory access patterns and privilege escalation attempts. The patch for this vulnerability specifically addresses the improper validation of memory protection masks in the ashmem driver, restoring proper access controls and preventing unauthorized manipulation of system memory resources.