CAPEC 69

Summary

Attack Execution Flow

1. The attacker probes for programs running with elevated privileges.

2. The attacker finds a bug in a program running with elevated privileges.

3. The attacker exploits the bug that she has found. For instance she can try to inject and execute arbitrary code or write to OS resources.

Likelihood: Very High

Low: An attacker can use a tool to scan and automatically launch an attack against known issues. A tool can also repeat a sequence of instructions and try to brute force the service on the host target, an example of that would be the flooding technique.

Medium to High: More advanced attack may require knowledge of the protocol spoken by the host service.

Probing technique include fuzzing (sending random data in order to fail the service on the host target), brute forcing (with automated tools), network scanning to determine which services are available and running on the target host.

There are freely available tools to probe and gather information from host target. For instance, the attacker can find out that a host target has not been patched by collecting such information.

The log can have a trace of abnormal activity. Also if abnormal activity is detected on the host target. For instance flooding should be seen as abnormal activity and the target host may decide to take appropriate action in order to mitigate the attack (data filtering or blocking). Resource exhaustion is also a sign of abnormal activity.

The attacker may try to hide her attack by forging the host's logs. The attacker has interest in mimicing a legitimate call to the program or service under threat.

Apply the principle of least privilege.

Validate all untrusted data.

Apply the latest patches.

Scan your services and disable the ones which are not needed and are exposed unnecessarily. Exposing programs increases the attack surface. Only expose the services which are needed and have security mechanisms such as authentication built around them.

Avoid revealing information about your system (e.g., version of the program) to anonymous users.

Make sure that your program or service fail safely. What happen if the communication protocol is interrupted suddenly? What happen if a parameter is missing? Does your system have resistance and resiliance to attack? Fail safely when a resource exhaustion occurs.

If possible use a sandbox model which limits the actions that programs can take. A sandbox restricts a program to a set of privileges and commands that make it difficult or impossible for the program to cause any damage.

Check your program for buffer overflow and format String vulnerabilities which can lead to execution of malicious code.

Monitor traffic and resource usage and pay attention if resource exhaustion occurs.

Protect your log file from unauthorized modification and log forging.

A user must be authenticated if she invokes a privileged program.

CWE : Failure to protect stored data from modification

CWE : Setting manipulation

CWE : Often Misused: Privilege Management

CWE : Permissions, Privileges, and Access Controls