Apple M-series chips are vulnerable to a side-channel attack called GoFetch, which exploits data memory-dependent prefetchers (DMPs) to extract secret encryption keys.
DMPs are a feature of some modern processors that use memory access patterns to predict which data might be useful, and preload that data into cache memory for fast access.
A group of researchers discovered that the DMP process in Apple M-series chips (M1, M2 and M3) could be probed using attacker-selected inputs, and its prefetching behavior analyzed to ultimately predict encryption keys generated by the intended target. The researchers published their findings in a paper shared on their website Thursday.
This bug can extract encryption keys, which is a problem for servers (using TLS) or for those organizations where users are encrypting information. Largely, it will probably be highly secure environments that need to worry the most over this, but any organization running Apple CPUs and using encryption should be concerned, John Bambanek, president of Bambanek Consulting, told SC Media in an email.
The researchers GoFetch exploit involves feeding guesses into the targeted cryptographic application and observing changes in memory access on the system indicating prefetching patterns. By refining their inputs based on the observed changes, and correlating signals from the DMP to bits of cryptographic data, an attacker could ultimately infer the targeted encryption keys.
This attack essentially circumvents the safeguards of constant-time cryptography, which prevents side-channel extraction of encryption keys by eliminating any relationship between secret data contents and their execution timing.
The GoFetch researchers demonstrated that their proof-of-concept exploit works against Go RSA-2048 encryption, OpenSSL Diffie-Hellman key exchange (DHKE), and even the post-quantum encryption protocols CRYSTALS-Kyber and CRYSTALS-Dilithium. The attack takes a minimum of about 49 minutes (against Go RSA keys) and up to 15 hours (against Dilithium keys) to complete on average.
The attack was primarily tested on Apples M1 processor, but the groups investigations of the M2 and M3 CPUs indicated similar DMP activation patterns, suggesting they are likely vulnerable to the same exploit, the researchers said.
The Intel 13th generation Raptor Lake processor also uses a DMP in its microarchitecture, but the researchers found it was not as susceptible to attack due to its more restrictive activation criteria.
As a microarchitectural hardware feature of Apple chips, the DMPs susceptible to GoFetch cannot be directly patched. However, some mitigations are available to prevent or lower the likelihood of attack.
The attack requires the attackers GoFetch process (which probes and monitors the DMP) to run locally on the same machine as the targeted process, so avoiding the installation of suspicious programs is one line of defense.
Apple cited the ability to enable data-independent timing (DIT) as a mitigation for GoFetch in an email to SC Media. Enabling DIT, which is available on M3 processors, disables the vulnerable DMP feature, Ars Technica reported.
The researchers also noted that DMP does not activate for processes running on Apples Icestorm efficiency cores. Restricting cryptographic processes to these smaller cores will prevent GoFetch attacks but will also likely result in a performance reduction.
Cryptographic software providers can also use techniques like input blinding to mask the contents being fetched, but this also presents challenges in terms of performance penalties. Overall, users are recommended to keep any cryptographic software up to date as providers make changes to counter side-channel attack risks.
The researchers have said they will be releasing the proof-of-concept soon, which will significantly lower the difficulty to exploit this bug, Bambenek commented. There isnt much for [users] to do except to wait for encryption software writers to release updates and to see whether those vendors will create a configurable option so CISOs can choose speed or higher security.
The GoFetch vulnerability was disclosed to Apple in December 2023 and the researchers paper states Apple was investigating the PoC. An Apple spokesperson expressed gratitude toward the researchers in a comment to SC Media without disclosing further details about an investigation.
The vulnerability was also reported to the Go Crypto, OpenSSL and CRYSTALS teams. Go Crypto said the attack was considered low severity, OpenSSL said local side-channel attacks fall outside of its threat model, and CRYSTALS acknowledged that hardware fixes would be needed to resolve the issue in the long term.
SC Media reached out to the GoFetch team to ask about industry reactions to their research and did not receive a reply.
Link:
GoFetch: Apple chips vulnerable to encryption key stealing attack - SC Media
- WhatsApp overhauling status tab with encrypted Snapchat Stories-like feature - 9 to 5 Mac [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- GOP demands inquiry into EPA use of encrypted messaging apps - CNET [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- Encryption Apps Help White House Staffers Leakand Maybe Break the Law - WIRED [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- World Wide Web Creator Calls for Internet Decentralization & Encryption - The Data Center Journal [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- What It Means to Have an 'Adult' Conversation on Encryption - Pacific Standard [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- Confide in me! Encryption app leaks sensitive info from Washington DC - SC Magazine UK [Last Updated On: February 21st, 2017] [Originally Added On: February 21st, 2017]
- Gmail v7.2 Prepares to Add Support for S/MIME Enhanced Encryption - XDA Developers (blog) [Last Updated On: February 26th, 2017] [Originally Added On: February 26th, 2017]
- Top 6 Data Encryption Solutions - The Merkle [Last Updated On: February 26th, 2017] [Originally Added On: February 26th, 2017]
- Your Guide to the Encryption Debate - Consumer Reports - ConsumerReports.org [Last Updated On: February 26th, 2017] [Originally Added On: February 26th, 2017]
- Google helps put aging SHA-1 encryption out to pasture - Engadget [Last Updated On: February 26th, 2017] [Originally Added On: February 26th, 2017]
- Decipher your Encryption Challenges - Infosecurity Magazine [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- How the Politics of Encryption Affects Government Adoption - Freedom to Tinker [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- How Encryption Makes Your Sensitive Cloud-Based Data an Asset, Not a Liability - Security Intelligence (blog) [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- Set up VMware VM Encryption for hypervisor-level security - TechTarget [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- How The Media Are Using Encryption Tools To Collect Anonymous Tips - NPR [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- Encryption patent that roiled Newegg is dead on appeal | Ars Technica - Ars Technica [Last Updated On: February 28th, 2017] [Originally Added On: February 28th, 2017]
- Research proposes 'full-journey' email encryption - The Stack [Last Updated On: March 1st, 2017] [Originally Added On: March 1st, 2017]
- Database-as-a-service platform introduces encryption-at-rest - BetaNews [Last Updated On: March 1st, 2017] [Originally Added On: March 1st, 2017]
- Encrypted Messaging Service 'Signal' Adds Video Call Option - Top Tech News [Last Updated On: March 2nd, 2017] [Originally Added On: March 2nd, 2017]
- Germany, France lobby hard for terror-busting encryption backdoors ... - The Register [Last Updated On: March 2nd, 2017] [Originally Added On: March 2nd, 2017]
- How to Send Encrypted Nudes, a Guide for the Discerning Lover - Inverse [Last Updated On: March 2nd, 2017] [Originally Added On: March 2nd, 2017]
- Ironclad Encryption Corporation Announces New Ticker Symbol OTCQB: IRNC - Yahoo Finance [Last Updated On: March 2nd, 2017] [Originally Added On: March 2nd, 2017]
- The Best Email Encryption Software of 2017 | Top Ten Reviews [Last Updated On: March 2nd, 2017] [Originally Added On: March 2nd, 2017]
- No, you shouldn't delete Signal or other encrypted apps - TechCrunch [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- Best encryption software: Top 5 - Computer Business Review [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- Encryption Backdoors, Vault 7, and the Jurassic Park Rule of Internet Security - Just Security [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- That Encrypted Chat App the White House Liked? Full of Holes - WIRED [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- What the CIA WikiLeaks Dump Tells Us: Encryption Works - New York Times [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- Snake-Oil Alert Encryption Does Not Prevent Mass-Snooping - Center for Research on Globalization [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- Customer Letter - Apple [Last Updated On: March 11th, 2017] [Originally Added On: March 11th, 2017]
- Don't Let WikiLeaks Scare You Off of Signal and Other Encrypted Chat Apps - WIRED [Last Updated On: March 12th, 2017] [Originally Added On: March 12th, 2017]
- BT to offer customers encryption service for data - Capacity Media (registration) [Last Updated On: March 12th, 2017] [Originally Added On: March 12th, 2017]
- Encryption - technet.microsoft.com [Last Updated On: March 12th, 2017] [Originally Added On: March 12th, 2017]
- Use FileVault to encrypt the startup disk on ... - Apple Support [Last Updated On: March 12th, 2017] [Originally Added On: March 12th, 2017]
- Viber launches secret chats to go beyond encryption - SlashGear [Last Updated On: March 13th, 2017] [Originally Added On: March 13th, 2017]
- Zix wins 5-vendor email encryption shootout - Network World [Last Updated On: March 13th, 2017] [Originally Added On: March 13th, 2017]
- A lesson from the CIA WikiLeaks dump: Encryption works - The Seattle Times [Last Updated On: March 13th, 2017] [Originally Added On: March 13th, 2017]
- What the CIA WikiLeaks Dump Tells Us: Encryption Works - NewsFactor Network [Last Updated On: March 18th, 2017] [Originally Added On: March 18th, 2017]
- Panicked Secret Service Says It Lost Encrypted Laptop But It's Fine, Everything's Fine - Gizmodo [Last Updated On: March 18th, 2017] [Originally Added On: March 18th, 2017]
- Google Cloud adds new customer-supplied encryption key partners ... - ZDNet [Last Updated On: March 18th, 2017] [Originally Added On: March 18th, 2017]
- Preseeding Full Disk Encryption - Linux Journal [Last Updated On: March 18th, 2017] [Originally Added On: March 18th, 2017]
- Bypassing encryption: 'Lawful hacking' is the next frontier of law enforcement technology - Boston Business Journal [Last Updated On: March 18th, 2017] [Originally Added On: March 18th, 2017]
- SecurityBrief NZ - Gemalto introduces on-prem encryption key solution for 'highly regulated' organisations - SecurityBrief NZ [Last Updated On: March 21st, 2017] [Originally Added On: March 21st, 2017]
- 'Always Be Concerned': US Court Slaps Down Fifth Amendment Defense of Encryption - Sputnik International [Last Updated On: March 21st, 2017] [Originally Added On: March 21st, 2017]
- Quantum Key System Uses Unbreakable Light-Based Encryption to Secure Data - Photonics.com [Last Updated On: March 21st, 2017] [Originally Added On: March 21st, 2017]
- Wikileaks Only Told You Half The Story -- Why Encryption Matters More Than Ever - Forbes [Last Updated On: March 21st, 2017] [Originally Added On: March 21st, 2017]
- EPA Sued For Withholding Info On Encrypted Text Messages | The ... - Daily Caller [Last Updated On: March 22nd, 2017] [Originally Added On: March 22nd, 2017]
- Opinion Data encryption efforts ramp up in face of growing security threats - Information Management [Last Updated On: March 22nd, 2017] [Originally Added On: March 22nd, 2017]
- Bypassing encryption: Lawful hacking is the next frontier of law enforcement technology - Salon [Last Updated On: March 22nd, 2017] [Originally Added On: March 22nd, 2017]
- NeuVector Announces Container Visualization, Encryption, and Security Solution for NGINX Plus - DABCC.com [Last Updated On: March 23rd, 2017] [Originally Added On: March 23rd, 2017]
- Is encryption one of the required HIPAA implementation specifications? - TechTarget [Last Updated On: March 23rd, 2017] [Originally Added On: March 23rd, 2017]
- Paper Spells Out Tech, Legal Options for Encryption Workarounds - Threatpost [Last Updated On: March 23rd, 2017] [Originally Added On: March 23rd, 2017]
- Encryption debate needs to be nuanced, says FBI's Comey - TechTarget [Last Updated On: March 25th, 2017] [Originally Added On: March 25th, 2017]
- Comey Renews Debate Over Encryption - 550 KTSA [Last Updated On: March 25th, 2017] [Originally Added On: March 25th, 2017]
- UK minister says encryption on messaging services is unacceptable - Reuters [Last Updated On: March 28th, 2017] [Originally Added On: March 28th, 2017]
- The why and how of encrypting files on your Android smartphone - Phoenix Sun [Last Updated On: March 28th, 2017] [Originally Added On: March 28th, 2017]
- UK targets WhatsApp encryption after London attack - Yahoo News [Last Updated On: March 28th, 2017] [Originally Added On: March 28th, 2017]
- Critical flaw alert! Stop using JSON encryption | InfoWorld - InfoWorld [Last Updated On: March 28th, 2017] [Originally Added On: March 28th, 2017]
- SecureMyEmail is email encryption for everyone - TechRepublic - TechRepublic [Last Updated On: March 28th, 2017] [Originally Added On: March 28th, 2017]
- Apple iOS 10.3 will introduce encryption which makes it MORE difficult for cops and spooks to crack into ISIS nuts ... - The Sun [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- How to Analyze An Encryption Access Proposal - Freedom to Tinker [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- Questions for the FBI on Encryption Mandates - Freedom to Tinker [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- Justice Department anti-terror chief keeps pressing on encryption - Politico (blog) [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- UK government can force encryption removal, but fears losing, experts say - The Guardian [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- Encryption FAQs [Last Updated On: March 29th, 2017] [Originally Added On: March 29th, 2017]
- Why isn't US military email protected by standard encryption tech? - Naked Security [Last Updated On: April 9th, 2017] [Originally Added On: April 9th, 2017]
- How have ARM TrustZone flaws affected Android encryption? - TechTarget [Last Updated On: April 9th, 2017] [Originally Added On: April 9th, 2017]
- Keeping the enterprise secure in the age of mass encryption - Information Age [Last Updated On: April 9th, 2017] [Originally Added On: April 9th, 2017]
- Lack of encryption led to Dallas siren hack - WFAA [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- Internet Society tells G20 nations: The web must be fully encrypted - The Register [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- Make Encryption Ubiquitous, Says Internet Society - Infosecurity ... - Infosecurity Magazine [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- Can we encrypt the web while giving governments a backdoor to snoop? - SC Magazine UK [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- Why we need to encrypt everything - InfoWorld [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- Hacked Dallas sirens get extra encryption to fend off future attacks - Computerworld [Last Updated On: April 12th, 2017] [Originally Added On: April 12th, 2017]
- SHA-1 Encryption Has Been Broken: Now What? - Forbes [Last Updated On: April 14th, 2017] [Originally Added On: April 14th, 2017]
- Hewlett Packard Enterprise touts encryption tool for federal clients - The Hill [Last Updated On: April 14th, 2017] [Originally Added On: April 14th, 2017]
- Encryption on the Rise in Age of Cloud - Infosecurity Magazine - Infosecurity Magazine [Last Updated On: April 14th, 2017] [Originally Added On: April 14th, 2017]
- Lawmaker Pushes Bill That Requires Encryption by Pennsylvania State Employees - Government Technology [Last Updated On: April 14th, 2017] [Originally Added On: April 14th, 2017]
- Disk encryption - Wikipedia [Last Updated On: April 14th, 2017] [Originally Added On: April 14th, 2017]
- The apps to use if you want to keep your messages private - Recode [Last Updated On: April 15th, 2017] [Originally Added On: April 15th, 2017]