CAPEC-237: Escaping a Sandbox by Calling Code in Another Language
Attack Pattern ID: 237
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.
Likelihood Of Attack
This table shows the other attack patterns and high level categories that are related to this attack pattern. These relationships are defined as ChildOf and ParentOf, and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as CanFollow, PeerOf, and CanAlsoBe are defined to show similar attack patterns that the user may want to explore.
Standard Attack Pattern - A standard level attack pattern in CAPEC is focused on a specific methodology or technique used in an attack. It is often seen as a singular piece of a fully executed attack. A standard attack pattern is meant to provide sufficient details to understand the specific technique and how it attempts to accomplish a desired goal. A standard level attack pattern is a specific type of a more abstract meta level attack pattern.
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.
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.
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.
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.
The attacker must have a good knowledge of the platform specific mechanisms of signing and verifying code. Most code signing and verification schemes are based on use of cryptography, the attacker needs to have an understand of these cryptographic operations in good detail.
None: No specialized resources are required to execute this type of attack.
This table specifies different individual consequences associated with the attack pattern. The Scope identifies the security property that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in their attack. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a pattern will be used to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.
Bypass Protection Mechanism
Execute Unauthorized Commands
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.
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.
A Related Weakness relationship associates a weakness with this attack pattern. Each association implies a weakness that must exist for a given attack to be successful. If multiple weaknesses are associated with the attack pattern, then any of the weaknesses (but not necessarily all) may be present for the attack to be successful. Each related weakness is identified by a CWE identifier.
[REF-91] J. Cappos, J. Rasley, J. Samuel, I. Beschastnikh, C. Barsan, A. Krishnamurthy
and T. Anderson. "Retaining Sandbox Containment Despite Bugs in Privileged Memory-Safe Code". The 17th ACM Conference on Computer and Communications Security (CCS '10). 2010.