CVE-2015-9190 in Android
Summary
by MITRE
In Android before 2018-04-05 or earlier security patch level on Qualcomm Snapdragon Mobile and Snapdragon Wear IPQ4019, MDM9206, MDM9607, MDM9615, MDM9625, MDM9635M, MSM8909W, SD 210/SD 212/SD 205, SD 400, SD 410/12, SD 600, SD 615/16/SD 415, SD 808, and SD 810, if start_addr + size is too large in boot_clobber_check_local_address_range(), an integer overflow occurs, resulting in clobber protection check being bypassed and SBL memory corruption.
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Analysis
by VulDB Data Team • 01/26/2020
This vulnerability exists within the Qualcomm Snapdragon mobile and wearable chipsets affecting Android devices patched before April 5th 2018. The flaw resides in the boot_clobber_check_local_address_range() function where an integer overflow occurs when calculating the sum of start_addr and size parameters. This overflow condition allows the clobber protection mechanism to be circumvented, enabling potential memory corruption in the SBL (Secondary Boot Loader) component. The vulnerability specifically impacts a wide range of Qualcomm SoCs including the Snapdragon 210, 400, 600, 800, and 810 series along with various MDM and IPQ4019 chipsets. The integer overflow occurs during address range validation, creating a scenario where the system fails to properly validate memory boundaries, potentially allowing malicious actors to overwrite critical boot components. This represents a critical security flaw that undermines the integrity of the device's boot process and could enable persistent rootkit-style attacks. The vulnerability aligns with CWE-191 Integer Underflow/Overflow, specifically involving unsigned integer overflow conditions that can lead to memory corruption and privilege escalation. From an operational perspective, this vulnerability provides attackers with the capability to modify boot loaders and potentially gain persistent control over the device before the operating system fully loads. The ATT&CK framework categorizes this under privilege escalation and defense evasion techniques, as it allows attackers to modify system boot components and bypass security checks that would normally prevent such modifications. The impact extends beyond simple memory corruption to potentially enable full device compromise, as the SBL is a critical component that loads and validates the operating system. This vulnerability exemplifies how hardware-level flaws in boot processors can create persistent attack vectors that remain effective even after OS-level patches are applied, as the underlying firmware and bootloader components may not be updated through standard Android patching processes.
The integer overflow vulnerability in boot_clobber_check_local_address_range() represents a fundamental flaw in the address validation logic of Qualcomm's boot components. When the calculation start_addr + size exceeds the maximum value that can be represented by the integer type used for the calculation, the result wraps around to a smaller value due to overflow behavior. This produces a false positive in the memory range validation, allowing malicious inputs to pass through what should be strict boundary checks. The vulnerability is particularly dangerous because it operates at the lowest level of the boot process, where system security is most critical and where attackers can establish persistent footholds. The affected Qualcomm SoCs are widely deployed across numerous Android devices, making this vulnerability exploitable across a broad range of consumer and enterprise mobile platforms. The bypass of clobber protection mechanisms means that attackers can potentially corrupt memory areas that should remain protected, including critical boot loader code sections. This flaw demonstrates the importance of proper integer overflow protection in security-critical code paths, especially in bootloaders where memory corruption can have system-wide consequences. The vulnerability's exploitation potential is enhanced by the fact that it occurs in the early boot phase, before many of the standard Android security mitigations are active, making it particularly effective for establishing persistent malicious control over the device. From a security architecture standpoint, this vulnerability highlights the challenges of securing boot processes in complex SoC environments where multiple processors and firmware components must work together to maintain system integrity. The issue also underscores the need for comprehensive security testing of low-level firmware components that operate outside the traditional software security model.
Mitigation strategies for this vulnerability must address both the immediate firmware-level concerns and the broader security implications of boot process compromise. Device manufacturers should implement comprehensive firmware updates that correct the integer overflow condition in the boot_clobber_check_local_address_range() function, ensuring that address range validation properly handles large address calculations. The fix should include proper integer overflow detection and handling, potentially through bounds checking or using larger integer types for address calculations. System administrators and security teams should conduct thorough inventory assessments to identify all affected devices and prioritize patching efforts, particularly for enterprise devices that may not receive automatic updates. Additional mitigations include implementing hardware-based security features such as memory protection units and secure boot mechanisms that can detect and prevent unauthorized memory modifications. The vulnerability highlights the importance of maintaining updated firmware across all system components, as bootloader-level flaws can persist even when operating system patches are applied. Security monitoring should include detection of anomalous boot process behavior and memory corruption patterns that might indicate exploitation attempts. Organizations should also consider implementing device management solutions that can enforce firmware update policies and track the security status of mobile devices across their networks. From a defensive perspective, this vulnerability reinforces the need for continuous security validation of hardware-level components and the importance of supply chain security practices to prevent such flaws from reaching production devices. The remediation process should also include verification testing to ensure that the patched firmware correctly handles boundary conditions without introducing new vulnerabilities.