CAPEC-237: Escaping a Sandbox by Calling Code in Another Language
CAPEC版本: 3.9
更新日期: 2023-01-24
攻击模式描述
The attacker may submit malicious code of another language to obtain access to privileges that were not intentionally exposed by the sandbox, thus escaping the sandbox. For instance, Java code cannot perform unsafe operations, such as modifying arbitrary memory locations, due to restrictions placed on it by the Byte code Verifier and the JVM. If allowed, Java code can call directly into native C code, which may perform unsafe operations, such as call system calls and modify arbitrary memory locations on their behalf. To provide isolation, Java does not grant untrusted code with unmediated access to native C code. Instead, the sandboxed code is typically allowed to call some subset of the pre-existing native code that is part of standard libraries.
执行流程
步骤 1 Explore
[Probing] The attacker probes the target application to see whether calling code of another language is allowed within a sandbox.
- The attacker probes the target application to see whether calling code of another language is allowed within a sandbox.
步骤 2 Explore
[Analysis] The attacker analyzes the target application to get a list of cross code weaknesses in the standard libraries of the sandbox.
- The attacker analyzes the target application to get a list of cross code weaknesses in the standard libraries of the sandbox.
步骤 3 Experiment
[Verify the exploitable security weaknesses] The attacker tries to craft malicious code of another language allowed by the sandbox to verify the security weaknesses of the standard libraries found in the Explore phase.
- The attacker tries to explore the security weaknesses by calling malicious code of another language allowed by the sandbox.
步骤 4 Exploit
[Exploit the security weaknesses in the standard libraries] The attacker calls malicious code of another language to exploit the security weaknesses in the standard libraries verified in the Experiment phase. The attacker will be able to obtain access to privileges that were not intentionally exposed by the sandbox, thus escaping the sandbox.
- The attacker calls malicious code of another language to exploit the security weaknesses in the standard libraries.
所需技能
所需资源
- None: No specialized resources are required to execute this type of attack.
后果影响
影响范围: Access Control Authorization
技术影响: Bypass Protection Mechanism
影响范围: Authorization
技术影响: Execute Unauthorized Commands
说明: Run Arbitrary Code
影响范围: Accountability Authentication Authorization Non-Repudiation
技术影响: Gain Privileges
缓解措施
Assurance: Sanitize the code of the standard libraries to make sure there is no security weaknesses in them.
Design: Use obfuscation and other techniques to prevent reverse engineering the standard libraries.
Assurance: Use static analysis tool to do code review and dynamic tool to do penetration test on the standard library.
Configuration: Get latest updates for the computer.
示例实例
Exploit: Java/ByteVerify.C is a detection of malicious code that attempts to exploit a vulnerability in the Microsoft Virtual Machine (VM). The VM enables Java programs to run on Windows platforms. The Microsoft Java VM is included in most versions of Windows and Internet Explorer. In some versions of the Microsoft VM, a vulnerability exists because of a flaw in the way the ByteCode Verifier checks code when it is initially being loaded by the Microsoft VM. The ByteCode Verifier is a low level process in the Microsoft VM that is responsible for checking the validity of code - or byte code - as it is initially being loaded into the Microsoft VM. Java/ByteVerify.C attempts to download a file named "msits.exe", located in the same virtual directory as the Java applet, into the Windows system folder, and with a random file name. It then tries to execute this specific file. This flaw enables attackers to execute arbitrary code on a user's machine such as writing, downloading and executing additional malware. This vulnerability is addressed by update MS03-011, released in 2003.