CVE-2020-0424 in Android
Summary
by MITRE • 11/10/2020
In send_vc of res_send.cpp, there is a possible out of bounds read due to an incorrect bounds check. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11 Android-9 Android-10Android ID: A-161362564
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/04/2020
The vulnerability identified as CVE-2020-0424 resides within the Android operating system's network resolution functionality, specifically in the send_vc function located in res_send.cpp. This issue represents a critical boundary condition flaw that affects multiple Android versions including Android 11, Android 9, and Android 10. The vulnerability manifests as an out-of-bounds read condition that occurs due to an incorrect bounds check implementation within the DNS resolution process. The affected component handles the sending of DNS queries and responses, making it a core element of the system's network communication infrastructure.
The technical flaw stems from insufficient validation of buffer boundaries when processing DNS response data. During normal operation, the system processes DNS queries and responses through the resolver functions, but the send_vc function fails to properly validate the length of incoming data before accessing memory regions. This incorrect bounds checking allows an attacker to potentially read memory locations that should remain inaccessible, leading to information disclosure. The vulnerability does not require any special privileges or user interaction for exploitation, making it particularly concerning as it can be triggered automatically during normal network operations. The out-of-bounds read can potentially expose sensitive data from adjacent memory regions, including potentially confidential information such as system pointers, authentication tokens, or other critical data structures that may be stored in memory.
The operational impact of this vulnerability extends beyond simple information disclosure, as it could potentially enable attackers to gather intelligence about the system's memory layout and internal structures. This information could be leveraged to craft more sophisticated attacks or to understand the system's security posture. The vulnerability affects the core DNS resolution functionality, which means it could be exploited during any network activity that triggers DNS lookups, including routine internet browsing, application network requests, or system network operations. The lack of requirement for additional execution privileges or user interaction makes this vulnerability particularly dangerous as it can be exploited silently in the background. According to industry standards, this vulnerability maps to CWE-129, which specifically addresses improper validation of the length of input data, and could potentially be categorized under ATT&CK technique T1059 for command and scripting interpreter usage if exploited in conjunction with other techniques.
Mitigation strategies for this vulnerability primarily involve applying the latest security patches provided by Google and device manufacturers. The Android security bulletin addressing this issue should be implemented immediately across all affected devices. Organizations should also consider network monitoring to detect unusual DNS query patterns that might indicate exploitation attempts. Additionally, implementing proper network segmentation and access controls can help limit the potential impact if exploitation occurs. Device administrators should ensure that all Android devices are kept up to date with the latest security patches, particularly those addressing memory safety issues. The vulnerability highlights the importance of robust input validation and bounds checking in system-level code, especially in components that handle network data processing. Regular security audits of core system libraries should be conducted to identify similar issues that may exist in other components of the operating system.