CVE-2021-0515 in Android
Summary
by MITRE • 07/15/2021
In Factory::CreateStrictFunctionMap of factory.cc, there is a possible out of bounds write due to an incorrect bounds check. This could lead to remote code execution in an unprivileged process with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-9 Android-10 Android-11 Android-8.1Android ID: A-167389063
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Analysis
by VulDB Data Team • 07/18/2021
The vulnerability identified as CVE-2021-0515 resides within the V8 JavaScript engine's factory.cc component, specifically in the Factory::CreateStrictFunctionMap method. This flaw represents a critical out-of-bounds write condition that arises from an inadequate bounds check implementation. The vulnerability affects multiple Android versions including Android 8.1, 9, 10, and 11, making it a widespread concern across the Android ecosystem. The issue stems from improper validation of array indices during function map creation, allowing malicious code to write data beyond the allocated memory boundaries.
The technical nature of this vulnerability aligns with CWE-129, which addresses insufficient bounds checking, and CWE-787, which covers out-of-bounds write conditions. The flaw operates at the memory management level where the V8 engine's factory component fails to properly validate the size of arrays before performing write operations. This particular implementation error occurs during the creation of strict function maps, which are fundamental data structures used in JavaScript execution contexts. The vulnerability's exploitation requires no user interaction, making it particularly dangerous as it can be triggered through automated means within web applications or malicious websites.
From an operational perspective, this vulnerability presents a severe remote code execution risk that can be exploited by attackers without requiring any additional privileges or execution contexts. The attack surface is broad since any application or web content running on affected Android versions could potentially serve as an attack vector. The unprivileged nature of the exploitation means that even sandboxed applications or web browsers could be compromised, leading to full system compromise. The vulnerability's impact extends beyond simple code execution as it can potentially allow attackers to bypass security restrictions and escalate privileges within the Android environment.
The mitigation strategies for CVE-2021-0515 primarily focus on updating to patched Android versions where Google has addressed the bounds checking implementation in the V8 engine. Organizations should prioritize immediate deployment of security patches, particularly for devices that handle untrusted web content or applications. Additional protective measures include implementing network-level restrictions, utilizing application sandboxing, and monitoring for suspicious network activity that might indicate exploitation attempts. The vulnerability's classification under the ATT&CK framework would fall under T1059.007 for JavaScript execution and potentially T1068 for local privilege escalation, though the initial exploitation does not require elevated privileges. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of the vulnerable V8 engine versions, particularly in enterprise environments where custom Android builds or modified applications might not receive automatic updates.