PS4 Hacking 9.03-9.04: BD-JB Blu-ray Disc Java Sandbox Escape by TheFloW!

While confirmed working by hacker theflow0 on PlayStation 4 consoles below 9.50 PS4 Firmware in addition to today's PS5 Hacking 4.51 (and Under), since the pOOBs4 PS4 Jailbreak 9.00 Exploit is already released much of the focus will be on PS4 Firmware 9.03 and PS4 Firmware 9.04 consoles for this latest BD-JB Blu-ray Disc Java Sandbox Escape unveiled at the HardWear.io Conference 2022 (Official Site) that does NOT allow PS4 Game Backups burned on Blu-ray Disc to be ran without a kernel exploit due to JIT capabilities being present... later clarifying, "because we don't have enough RAM in the BD-J process and there are some other constraints. It was only a theoretical impact."

Download: 2022-hardwear-io-bd-jb.pdf (444 KB)

The current system software is 9.60 PS4 Firmware, and according to the Tweets below Andy Nguyen's talk video will be uploaded in a few weeks... until then those in the PS4Scene can check out the latest PlayStation Hacktivity disclosure from theflow0 via HackerOne.com below: BD-J Exploit Chain

Hey PlayStation!

Below are 5 vulnerabilities chained together that allows an attacker to gain JIT capabilities and execute arbitrary payloads. The provided payload triggers a buffer overflow that causes a kernel panic. Please consider each of the vulnerabilities individually. AFAIK, this is the first exploit chain that is being submitted to you

Vulnerabilities

[MEDIUM][PS4] [PS5] Vulnerability 1

The class com.sony.gemstack.org.dvb.user.UserPreferenceManagerImpl deserializes the userprefs file under privileged context using readObject() which is insecure:

Code:

 private void initPreferences() {
        try {
            UserPreferenceManagerImpl.preferences = AccessController.doPrivileged((PrivilegedExceptionAction<String[][]>)new ReadPreferenceAction());
        }
        catch (PrivilegedActionException ex) {}
        if (UserPreferenceManagerImpl.preferences == null) {
            UserPreferenceManagerImpl.preferences = new String[UserPreferenceManagerImpl.PREFERENCES.length][];
        }
        if (UserPreferenceManagerImpl.preferences[3] == null) {
            UserPreferenceManagerImpl.preferences[3] = new String[] { "26" };
            this.savePreferences();
        }
    }

Code:

private static class ReadPreferenceAction implements PrivilegedExceptionAction
    {
        public Object run() throws Exception {
            String[][] array = null;
            ObjectInputStream objectInputStream = null;
            try {
                objectInputStream = new ObjectInputStream(new BufferedInputStream(new FileInputStream(RootCertManager.getOriginalPersistentRoot() + "/userprefs")));
                array = (String[][])objectInputStream.readObject();
            }
            finally {
                if (objectInputStream != null) {
                    objectInputStream.close();
                }
            }
            return array;
        }
    }

An attacker can replace the userprefs file with a malicious serialized object to instantiate classes under privileged context. On older firmwares such as 5.05, where the commit is not present, exploitation of this vulnerability is easy: An attacker can instantiate a ClassLoader subclass to call defineClass with all permissions and finally bypass the security manager.

[MEDIUM][PS4] Vulnerability 2

The class com.oracle.security.Service contains a method newInstance which calls Class.forName on an arbitrary class name. This allows arbitrary classes, even restricted ones (for example in sun.), to be instantiated. This works for all classes with public constructors that have single arguments. The check in newInstance can be bypassed by calling com.oracle.ProviderAdapter.setProviderAccessor on a custom ProviderAccessor implementation.

Code:

       if (!this.registered) {
            if (ProviderAdapter.getService(this.provider, this.type, this.algorithm) != this) {
                throw new NoSuchAlgorithmException("Service not registered with Provider " + this.provider.getName() + ": " + this);
            }
            this.registered = true;
        }

[MEDIUM][PS4] [PS5] Vulnerability 3

The class com.sony.gemstack.org.dvb.io.ixc.IxcProxy contains the protected method invokeMethod which can call methods under privileged context. Permission checks in methods can be bypassed if the following conditions are met:

The method is public and non-static.
The method's class is public, non-final and can be instantiated.

In such a scenario, an attacker can write a subclass of the target class which implements an interface where the desired method throws RemoteException.

For example, there are permission checks in File.list(). An attacker can bypass them with the following classes:

Code:

class FileImpl extends File implements FileInterface {
  FileImpl(String pathname) {
    super(pathname);
  }

Code:

interface FileInterface extends Remote {
  public String[] list() throws RemoteException;
}

This vulnerability can be used to leak the file system structure as well as dumping files (for example from /app0/).

[HIGH][PS4] Vulnerability 4

The "compiler receiver thread" receives a structure of size 0x58 bytes from the runtime process:

Code:

typedef struct {
  uint8_t cmd; // 0x00
  uint64_t arg0; // 0x08
  uint64_t arg1; // 0x10
  uint64_t arg2; // 0x18
  uint64_t arg3; // 0x20
  uint64_t arg4; // 0x28
  uintptr_t runtime_data; // 0x30
  uintptr_t compiler_data; // 0x38
  uint64_t data1; // 0x40
  uint64_t data2; // 0x48
  uint64_t unk; // 0x50
} CompilerAgentRequest; // 0x58

CompilerAgentRequest req;
while (CompilerAgent::readn(s, &req, sizeof(req)) > 0) {
  uint8_t ack = 0xAA;
  CompilerAgent::writen(s, &ack, sizeof(ack));
  if (req.compiler_data != 0) {
    memcpy(req.compiler_data + 0x28, &req, sizeof(req));
    ...
  }
  ...
}

This struct contains a pointer at offset 0x38 (we call it compiler_data) from the compiler process which is used to make a backup of the request structure. An attacker can simply send an untrusted pointer and the compiler receiver thread will copy data from the request into its memory. In other words, we have a write-what-where primitive. An attacker can exploit this vulnerability by supplying a pointer to JIT memory and store the content to be written in the request. The compiler will write this data into JIT memory and therefore give us the opportunity to execute arbitrary payloads. This has severe implications:

An ELF loader can be written to load and execute p!rated games.
Kernel exploitation becomes trivial as there is no SMEP and one can simply jump to user with a corrupted function pointer.

[HIGH][PS4] [PS5] Vulnerability 5

The UDF driver is used on the PS4 and PS5 which contains a buffer overflow. An attacker can make the size inf_len larger than sector_size (the assumption of internal allocation is that the data is smaller than the sector size) and cause an overflow with memcpy().

Code:

int
udf_read_internal(struct udf_node *node, uint8_t *blob)
{
    struct file_entry *fe = node->fe;
    struct extfile_entry *efe = node->efe;
    struct udf_mount *ump;
    uint64_t inflen;
    int addr_type, icbflags;
    uint32_t sector_size;
    uint8_t *pos;

    /* get extent and do some paranoia checks */
    ump = node->ump;
    sector_size = ump->sector_size;

    if (fe != NULL) {
        inflen = le64toh(fe->inf_len);
        pos = &fe->data[0] + le32toh(fe->l_ea);
        icbflags = le16toh(fe->icbtag.flags);
    } else {
        inflen = le64toh(efe->inf_len);
        pos = &efe->data[0] + le32toh(efe->l_ea);
        icbflags = le16toh(efe->icbtag.flags);
    }
    addr_type = icbflags & UDF_ICB_TAG_FLAGS_ALLOC_MASK;

    /* copy out info */
    memset(blob, 0, sector_size);
    memcpy(blob, pos, inflen);

    return (0);
}

Proof-of-concept

Attached is the exploit chain bd-jb as a .iso file which demonstrates the exploitation of vulnerabilities 1-4 that demonstrates the ability to run arbitrary payloads. Burn the iso image with UDF 2.5 file system. You can send the payload using nc $PS4IP 1337 < payload.bin. The provided payload causes a kernel panic by triggering vulnerability 5 (the file /PWN/0 has been modified to use internal allocation and has a size of 4MB filled with A). Tested on latest firmware 9.00.

Impact

With these vulnerabilities, it is possible to ship p!rated games on bluray discs. That is possible even without a kernel exploit as we have JIT capabilities.

For those new to the PlayStation 4 Scene, this comes following the launch of homebrew site Blu-Play.com alongside several related articles (sorted by date below, with the oldest first):

Advantages of BD-JB compared to WebKit exploit:

Works on both PS4/PS5
100% reliable
Firmware-agnostic (ROP-less code execution)
Bigger kernel attack surface
JIT for executing payloads, so you can write a kernel exploit in C (on PS4 only)

CTurt on FreeDVDBoot for PS3 / PS4 and Blu-ray BD-J Attacks

BD-JB: Blu-ray Disc Java Sandbox Escape by Andy Nguyen via HardWear.io

BD-JB: Blu-ray Disc Java Sandbox Escape by Andy Nguyen | HardWear.io USA 2022

The King of PlayStation Jailbreaks shared his latest adventure on hacking PS5 ! PS5's AMD CPU supports eXecute memory only (XOM). Watch this amazing talk to experience Andy's (also known as theflow0) journey in PS5 Jailbreak along with live demo.