CVE-2017-0422 in Android
Summary
by MITRE
A denial of service vulnerability in Bionic DNS could enable a remote attacker to use a specially crafted network packet to cause a device hang or reboot. This issue is rated as High due to the possibility of remote denial of service. Product: Android. Versions: 4.4.4, 5.0.2, 5.1.1, 6.0, 6.0.1, 7.0, 7.1.1. Android ID: A-32322088.
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Analysis
by VulDB Data Team • 11/12/2022
The vulnerability identified as CVE-2017-0422 represents a critical denial of service flaw within the Bionic DNS implementation of Android operating systems. This weakness resides in the core networking stack that handles domain name resolution operations, making it a fundamental component that affects device stability and availability. The issue manifests when specifically crafted network packets are processed by the DNS resolver, triggering unexpected behavior that can result in complete system hang or forced reboot of affected devices. The vulnerability impacts a wide range of Android versions including 4.4.4, 5.0.2, 5.1.1, 6.0, 6.0.1, 7.0, and 7.1.1, indicating a long-standing problem that persisted across multiple major releases of the platform.
The technical nature of this flaw involves improper handling of malformed or specially constructed DNS packets within the Bionic libc library's DNS resolution mechanisms. When an attacker sends malicious DNS responses or crafted packets to a vulnerable device, the system's DNS resolver fails to properly validate input data, leading to memory corruption or execution flow disruption. This type of vulnerability falls under CWE-129, which addresses improper validation of input boundaries, and can be classified as a buffer over-read or memory corruption issue within the DNS parsing code. The vulnerability operates at the network protocol level, specifically targeting the DNS resolution process that occurs when devices attempt to translate domain names into IP addresses for network communication.
The operational impact of CVE-2017-0422 extends beyond simple service disruption, as it can effectively render affected devices unusable until manual reboot or system recovery occurs. This makes it particularly dangerous in environments where device availability is critical, such as enterprise deployments, industrial control systems, or mobile devices used in mission-critical applications. Remote exploitation of this vulnerability allows attackers to perform denial of service attacks without requiring any authentication or physical access to the target device. The attack surface is broad since DNS resolution occurs frequently during normal device operation, making continuous exploitation possible and potentially devastating for user experience and system reliability. This vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and represents a classic example of how network protocol implementations can create systemic stability risks.
Mitigation strategies for this vulnerability primarily involve applying security patches released by Google as part of their regular Android security updates. Organizations should prioritize immediate deployment of the relevant security fixes to all affected Android devices within their environment. Network administrators can implement additional protective measures such as DNS filtering and monitoring for suspicious packet patterns, though these approaches provide only partial protection since the vulnerability can be triggered through various attack vectors. Device manufacturers should ensure that their update mechanisms are functioning properly to deliver patches to end users promptly, as many users may not manually update their systems. The vulnerability demonstrates the importance of robust input validation in system libraries and highlights how fundamental components like DNS resolvers require extensive security testing to prevent exploitation. Regular security assessments of network protocol implementations and adherence to secure coding practices are essential to prevent similar issues from emerging in future system implementations.