ÆPIC Leak
ÆPIC Leak

        
                
                    
                
                
                    
                    Architecturally Leaking Uninitialized Data from the Microarchitecture
                    ÆPIC Leak is the first CPU bug able to architecturally disclose sensitive data.
                        It leverages a vulnerability in recent Intel CPUs to leak secrets from the processor itself: on
                        most
                        10th, 11th and 12th generation Intel CPUs the APIC MMIO undefined range
                        incorrectly
                        returns stale data from the cache hierarchy.
                    In contrast to transient execution attacks like Meltdown and Spectre, ÆPIC Leak is an architectural
                            bug: the sensitive data gets directly disclosed without relying on any (noisy) side
                        channel.
                    ÆPIC Leak is like an uninitialized
                            memory read in the CPU itself.

                    A privileged attacker (Administrator or root) is required to access
                        APIC MMIO. Thus, most systems are safe from ÆPIC Leak.
                        However, systems relying on SGX to protect data from privileged attackers would be at risk,
                        thus, have to be patched.
                    
                    
                
                
                            @inproceedings{Borrello2022AEPIC,
    title = {{ÆPIC Leak}: Architecturally Leaking Uninitialized Data from the Microarchitecture},
    author = {Borrello, Pietro and Kogler, Andreas and Schwarzl, Martin and Lipp, Moritz and Gruss, Daniel and Schwarz, Michael},
    booktitle = {31st USENIX Security Symposium (USENIX Security 22)},
    year = {2022},
}
                        
            
        
                        Who is behind ÆPIC Leak?
                        
                    
        
                
                        ÆPIC Leak in Action
                        In our demo, we show how an attacker can disclose data from a protected SGX
                            enclave.
                        
                    
                
                    
                        
                            
                            To view this video please enable JavaScript, and consider upgrading to
                                a web browser that supports HTML5 video
                        
                    
                    
                        
                            
                            To view this video please enable JavaScript, and consider upgrading to
                                a web browser that supports HTML5 video
                        
                    
                
            
        
                        Questions & Answers
                        
                            
                                    If you have a recent Intel CPU probably yes. But if you do not rely on SGX, you
                                        don't have to worry.
                                    Intel provides a list with all affected products here and the technical advisory.
                                
                            
                                    No, in our current assessment, we believe that ÆPIC Leak is only relevant
                                            to Intel SGX enclaves. ÆPIC Leak requires access to the
                                        physical APIC MMIO page that can be achieved only with a
                                        high privileges. Traditional applications do not have to worry
                                        about ÆPIC Leak.
                                    
                                    
                                        Virtual Machines have no access to physical memory since no hypervisor
                                            allows it. We empirically verified that APIC virtualization (Intel
                                        APICv) is not affected by ÆPIC Leak.
                                    
                                
                            
                                Intel Software
                                            Guard eXtensions (SGX) is an innovative processor technology released in
                                        2015 to create isolated environments in the computer's memory, so-called
                                        enclaves. SGX acts like a secure vault in the processor itself, combining strong
                                        encryption and hardware-level isolation to safeguard enclave programs, and the
                                        data they operate on, even against very advanced types of malware that
                                            compromise the operating system, hypervisor, or firmware (BIOS).
                                    
                            
                            
                                
                                        The Advanced Programmable Interrupt Controller (APIC) is an
                                        integrated CPU
                                        component responsible for accepting, prioritizing, and dispatching
                                        interrupts to
                                        processors. The APIC can operate in xAPIC mode, in
                                        which APIC configuration registers are exposed through a memory-mapped I/O
                                        (MMIO)
                                        page.
                                    
                            
                            
                                No. This is a bug in the processor. Software can work around this bug, which
                                        costs performance. Future processors will have integrated fixes.
                            
                            
                            
                                This is not a transient execution attack, thus, it bypasses all
                                        existing mitigations. Intel released microcode and SGX SDK updates to fix the
                                        issue.
                            
                            
                                We do not have any data on this. The exploitation might not leave any traces in
                                        traditional log files.
                            
                        
                            If your system is affected, our proof-of-concept ÆPIC Leak exploit can read stale
                                    data, which may correspond to data previously accessed by the same processor
                                    core.
                                
                        
                        
                            We don't know. But probably not.
                        
                        
                            Yes, there is an academic paper.
                        
                        
                            CVE-2022-21233 is the official reference to ÆPIC Leak.
                                    CVE is the Standard
                                    for Information Security Vulnerability Names maintained by MITRE.
                                
                        
                        
                                The logo is free to use, rights waived via CC0. Logo designed
                                    by Theresa Dachauer.
                                
                                
                                    
                                        
                                            
                                            SVG
                                            PNG
                                        
                                    

                                    
                                        
                                            Logo
                                            
                                            
                                        
                                    
                                
                            
                        
                                Yes, there is a  GitHub
                                        repository containing source code for the ÆPIC Leak attack.
                                In alternative, here is a minimal PoC of ÆPIC Leak:
                                u8* apic_base = map_phys_addr(0xFEE00000);
dump(apic_base);
                            
                    
        
                        Acknowledgements
                        We would like to thank Intel
                            for working with us during the responsible disclosure.
                        Funding for part of this research was provided by
                            generous gifts from Amazon and Red Hat.
                    
        
    