CVE-2022-20165 in Android
Summary
by MITRE • 06/15/2022
In asn1_parse of asn1.c, there is a possible out of bounds read due to an incorrect bounds check. This could lead to local information disclosure with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-220868345References: N/A
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Analysis
by VulDB Data Team • 06/15/2022
The vulnerability identified as CVE-2022-20165 represents a critical out-of-bounds read condition within the Android kernel's ASN.1 parsing functionality. This flaw exists in the asn1_parse function located in the asn1.c source file, where an incorrect bounds check implementation creates a pathway for memory access violations. The vulnerability specifically affects Android kernel versions and has been assigned the Android ID A-220868345, indicating its severity and impact within the Android security ecosystem. The issue stems from improper validation of input data boundaries during ASN.1 (Abstract Syntax Notation One) parsing operations, which are fundamental to various cryptographic and network protocol implementations within the Android operating system.
The technical implementation of this vulnerability allows for a local information disclosure attack that requires system execution privileges to exploit successfully. This means that an attacker with root-level access or equivalent system privileges can leverage this flaw to read memory locations beyond the intended bounds of the ASN.1 parsing buffer. The out-of-bounds read occurs during the parsing of ASN.1 encoded data structures, which are commonly used in cryptographic protocols, certificate handling, and network communication frameworks within Android systems. This type of vulnerability falls under CWE-129, which specifically addresses "Improper Validation of Array Index," and represents a classic example of how insufficient bounds checking can lead to memory corruption issues. The attack vector does not require user interaction, making it particularly dangerous as it can be exploited automatically by malicious processes running with system privileges.
The operational impact of CVE-2022-20165 extends beyond simple information disclosure, as it can potentially enable attackers to extract sensitive kernel memory contents that may include cryptographic keys, credentials, or other confidential system information. This vulnerability essentially provides an attacker with a mechanism to bypass normal memory protection boundaries within the Android kernel, potentially leading to privilege escalation or further exploitation of other system components. The requirement for system execution privileges means that this vulnerability is particularly concerning in environments where root access is available, such as compromised devices or systems with weak security controls. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving privilege escalation and credential access, specifically mapping to T1068 (Local Privilege Escalation) and T1552 (Unsecured Credentials) tactics. The vulnerability's impact is amplified by its location within kernel-level code, where memory access violations can lead to system instability or complete compromise of the device's security posture.
Mitigation strategies for CVE-2022-20165 should focus on immediate patch deployment from Android security updates, which typically include corrected bounds checking implementations in the ASN.1 parsing functions. Organizations should prioritize updating their Android devices to the latest kernel versions that contain the patched asn1.c implementation. Additionally, system administrators should implement monitoring for unusual memory access patterns or potential exploitation attempts within kernel space. The fix typically involves correcting the bounds validation logic to properly check array indices against the actual buffer size before any memory read operations occur. Security teams should also consider implementing runtime protections such as stack canaries, address space layout randomization, and kernel memory protection mechanisms to reduce the effectiveness of potential exploitation attempts. Regular security assessments of kernel modules and cryptographic implementations should be conducted to identify similar bounds checking vulnerabilities that may exist in other system components.