CVE-2018-9389 in Android
Summary
by MITRE • 01/18/2025
In ip6_append_data of ip6_output.c, there is a possible way to achieve code execution due to a heap buffer overflow. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 01/18/2025
The vulnerability identified as CVE-2018-9389 represents a critical heap buffer overflow flaw within the IPv6 networking stack of the Linux kernel. This issue resides in the ip6_append_data function located in the ip6_output.c source file, making it a fundamental component of the kernel's network processing capabilities. The flaw manifests when handling IPv6 packet data transmission, specifically during the appending of data to network buffers, creating a condition where maliciously crafted network packets can trigger memory corruption.
The technical nature of this vulnerability stems from inadequate bounds checking during heap memory allocation and data copying operations. When the kernel processes IPv6 packets, the ip6_append_data function fails to properly validate the size of data being appended to dynamically allocated memory buffers. This allows an attacker to write beyond the allocated buffer boundaries, potentially overwriting adjacent memory locations including metadata used by the heap allocator. The vulnerability's classification as a heap buffer overflow aligns with CWE-121, which specifically addresses stack and heap buffer overflow conditions that can result in arbitrary code execution.
The operational impact of CVE-2018-9389 is particularly severe as it enables local privilege escalation without requiring any special privileges or user interaction. An attacker with basic system access can exploit this vulnerability to elevate their privileges to root level, effectively gaining complete control over the compromised system. This characteristic makes the vulnerability particularly dangerous in multi-user environments where unprivileged users might exploit it to gain administrative access. The lack of user interaction requirement means the vulnerability can be exploited automatically, making it a prime target for automated attack tools and malicious software.
From a cybersecurity perspective, this vulnerability demonstrates the critical importance of proper memory management in kernel space operations. The flaw represents a classic example of how network stack implementations can become attack vectors when proper input validation and memory bounds checking are absent. The vulnerability's exploitation pathway follows ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation', where attackers leverage system vulnerabilities to gain elevated privileges. Network protocol handlers in kernel space are particularly attractive targets for adversaries because successful exploitation can result in persistent system compromise with minimal detection risk.
The mitigation strategy for CVE-2018-9389 requires immediate kernel updates and patches from the Linux kernel maintainers. Organizations should prioritize patching systems running affected kernel versions, typically those prior to kernel version 4.16.10. Additionally, network administrators should implement monitoring solutions to detect unusual network traffic patterns that might indicate exploitation attempts. The vulnerability's nature suggests that defensive measures should include kernel hardening techniques such as stack canaries, address space layout randomization, and heap metadata protection. System administrators should also consider implementing network segmentation and access controls to limit potential attack vectors, while maintaining regular vulnerability assessments to identify similar issues in other kernel components.