CVE-2021-4064 in Chrome
Summary
by MITRE • 12/23/2021
Use after free in screen capture in Google Chrome on ChromeOS prior to 96.0.4664.93 allowed a remote attacker to potentially exploit heap corruption via a crafted HTML page.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 12/23/2021
This vulnerability represents a critical use-after-free condition affecting google chrome's screen capture functionality within chromeos environments. The flaw occurs when chrome processes screen capture requests and fails to properly manage memory references after objects have been freed from the heap. This particular issue affects versions prior to 96.0.4664.93 and enables remote code execution through maliciously crafted html pages that trigger the vulnerable screen capture api.
The technical implementation of this vulnerability stems from improper memory management within chrome's handling of screen capture operations. When a webpage attempts to utilize the screen capture functionality, chrome allocates memory for the capture operation and subsequently frees it upon completion. However, under certain conditions, references to this freed memory remain accessible to the malicious page, allowing an attacker to manipulate the heap state. This creates opportunities for heap corruption that can be exploited to execute arbitrary code within the chrome sandbox environment.
From an operational perspective this vulnerability poses significant risk as it requires no local privileges or user interaction beyond visiting a malicious webpage. The attack vector operates entirely through web-based exploitation making it particularly dangerous in enterprise environments where users may encounter compromised content in email, web browsing, or collaborative applications. The vulnerability falls under the common weakness enumeration category CWE-416 which specifically addresses use-after-free conditions, and aligns with attack techniques documented in the mitre att&ck framework under T1059 for command and scripting interpreter and T1203 for exploitation for client execution.
The impact of successful exploitation extends beyond simple code execution as it can potentially allow attackers to bypass chrome's security model and escalate privileges within the operating system. Since chromeos operates with a more restricted environment compared to traditional desktop operating systems, exploitation of this vulnerability could provide attackers with access to sensitive user data, file system operations, or network communications that would normally be protected by chrome's sandboxing mechanisms. Organizations running affected chromeos versions should immediately implement patch management procedures to ensure all devices receive the security update that resolves this memory corruption issue.
Mitigation strategies for this vulnerability include immediate deployment of chrome version 96.0.4664.93 or later which contains the necessary patches to prevent the use-after-free condition. Additionally administrators should consider implementing network-based protections such as content filtering and web application firewalls to block access to known malicious domains until patching can be completed. Security teams should also monitor for indicators of compromise related to this vulnerability through endpoint detection and response systems that can detect anomalous behavior patterns associated with heap corruption attempts. The remediation process should include comprehensive testing of the patched environment to ensure that legitimate screen capture functionality remains operational while eliminating the security risk posed by this use-after-free vulnerability.