Incident: iPhone Passcode Hack via NAND Mirroring by Cambridge Researcher

Published Date: 2016-09-20

Postmortem Analysis
Timeline 1. The software failure incident, where Sergei Skorobogatov demonstrated the NAND mirroring technique to unlock iPhones, happened in September 2016 as per the article published on September 20, 2016 [Article 47722].
System 1. iPhone security system, specifically the passcode protection mechanism [47722]
Responsible Organization 1. The FBI [47722]
Impacted Organization 1. The FBI [47722] 2. Apple [47722]
Software Causes 1. The software cause of the failure incident was the vulnerability in the iPhone's security system that allowed for the bypassing of the limit on password retry attempts, enabling the use of the NAND mirroring technique to break into the device [47722].
Non-software Causes 1. Physical vulnerability of the iPhone's hardware components, specifically the NAND chip, which allowed for the bypassing of the password retry limit [47722].
Impacts 1. The software failure incident led to the FBI paying over $1.3 million to unlock the San Bernardino shooter's iPhone 5C, which was later proven to be hackable using a cheaper method involving NAND mirroring [47722]. 2. The incident highlighted the potential security vulnerabilities in Apple devices, specifically iPhones up to the iPhone 6, raising concerns about the effectiveness of the security measures in place [47722]. 3. The failure incident resulted in a public dispute between Apple and the US government regarding access to encrypted communications and the implications of creating backdoor access to devices, leading to legal and PR battles [47722]. 4. The incident showcased the importance of continuously improving law enforcement's capabilities to handle encrypted communications and devices rather than seeking legislative measures that could weaken overall security [47722].
Preventions 1. Implementing stronger security measures in Apple devices to prevent unauthorized access through techniques like NAND mirroring [47722]. 2. Enhancing the encryption and security protocols in iPhones to make it more difficult for unauthorized parties to hack into the devices [47722]. 3. Collaborating with security researchers and experts to identify potential vulnerabilities and address them before they can be exploited by malicious actors [47722].
Fixes 1. Enhancing encryption and security measures in Apple devices to prevent unauthorized access through techniques like NAND mirroring [47722]. 2. Developing more sophisticated hardware and security features for newer iPhone models like the iPhone 6S and iPhone 7 to mitigate vulnerabilities exploited in the hack [47722]. 3. Strengthening law enforcement capabilities to handle encrypted communications and devices effectively, rather than seeking backdoor access that could compromise overall security [47722].
References 1. Sergei Skorobogatov, computer scientist from Cambridge University [47722] 2. FBI director, James Comey [47722] 3. Security and policy researcher Susan Landau [47722]

Software Taxonomy of Faults

Category Option Rationale
Recurring one_organization, multiple_organization (a) The software failure incident of being able to hack into iPhones using the NAND mirroring technique has happened again within the same organization, Apple. Sergei Skorobogatov demonstrated the technique to break into various iPhone models, including the iPhone 5C and up to the iPhone 6. This incident is reminiscent of the FBI's previous struggle to unlock the iPhone of the San Bernardino shooter, which led to the FBI paying over $1.3m to a third party for software to hack into the device [47722]. (b) The software failure incident of being able to hack into iPhones using the NAND mirroring technique has implications beyond just Apple products. The technique could potentially be used on newer models like the iPhone 6S and iPhone 7, although it would require more sophisticated hardware. This indicates that the vulnerability exploited by Skorobogatov's technique could extend to other organizations producing similar devices with NAND chips for memory storage [47722].
Phase (Design/Operation) design, operation (a) The software failure incident related to the design phase can be seen in the article where the FBI had initially paid over $1.3m to unlock the San Bernardino shooter's iPhone 5C. The FBI had considered various techniques, including the NAND mirroring approach, to unlock the phone. However, initially, the FBI director, James Comey, dismissed the technique as unworkable. It was only after Sergei Skorobogatov from Cambridge University demonstrated the technique through a paper and a YouTube video that it was proven to be effective. This highlights a failure in the initial design or consideration of potential methods to unlock the iPhone [47722]. (b) The software failure incident related to the operation phase can be observed in the same article where the FBI had to resort to paying a third party for software to hack into the iPhone of the San Bernardino gunman. This was due to the operation or misuse of the system, as Apple had declined to help the FBI break into the phone, leading to the FBI seeking alternative methods to access the phone's contents. The operation phase failure is evident in the need to pay a third party for software to gain access to the iPhone [47722].
Boundary (Internal/External) within_system, outside_system (a) within_system: The software failure incident in this case can be attributed to factors originating from within the system. The failure occurred due to a vulnerability in the iPhone's security system that allowed for the bypassing of the password retry limit through a technique known as NAND mirroring. This technique involved manipulating the phone's NAND chip to create cloned versions with the password attempt counter set to zero, enabling multiple password attempts until the phone was unlocked [47722]. (b) outside_system: The incident also involved external factors such as the FBI's initial inability to unlock the iPhone, leading them to pay a third party over $1.3 million for software to hack into the device. Additionally, there was a legal and PR battle between Apple and the US government regarding providing backdoor access to the phone, highlighting external pressures and conflicts surrounding the software failure incident [47722].
Nature (Human/Non-human) non-human_actions, human_actions (a) The software failure incident related to non-human actions: The software failure incident in this case was not directly caused by non-human actions. Instead, it was a result of a technique known as NAND mirroring, which involved manipulating the iPhone's memory system to bypass the password retry limit [Article 47722]. (b) The software failure incident related to human actions: The software failure incident in this case was influenced by human actions. The FBI paid a significant amount of money to unlock the San Bernardino shooter's iPhone, and there was a dispute between Apple and the US government regarding providing backdoor access to the phone [Article 47722].
Dimension (Hardware/Software) hardware (a) The software failure incident in the articles is related to hardware. The failure occurred due to a hardware-based technique known as NAND mirroring, where the researcher, Sergei Skorobogatov, manipulated the phone's NAND chip to bypass the limit on password retry attempts. This hardware-based approach allowed for breaking into the iPhone by creating a cloned version of the chip with the password attempt counter set to zero, enabling multiple attempts to unlock the phone [47722]. (b) The software failure incident is not directly related to software issues but rather to a hardware-based technique used to bypass the software security measures on the iPhone. The failure was not caused by software bugs or faults but by exploiting the hardware design of the device to gain unauthorized access to the phone's contents.
Objective (Malicious/Non-malicious) malicious (a) The objective of the software failure incident was malicious. The incident involved a computer scientist demonstrating a technique known as NAND mirroring to hack into iPhones, including the iPhone 5C used by the San Bernardino shooter. This technique allowed for bypassing the limit on password retry attempts and creating cloned versions of the NAND chip with the password attempt counter set to zero, enabling multiple attempts to unlock the phone [47722]. The FBI had previously paid a significant amount to a third party for software to hack into the iPhone, and the technique demonstrated by the computer scientist proved that the FBI's claim that such methods were impossible was incorrect [47722].
Intent (Poor/Accidental Decisions) poor_decisions (a) The intent of the software failure incident related to poor_decisions: - The FBI paid over $1.3m to unlock the San Bernardino shooter's iPhone 5C [Article 47722]. - The FBI initially dismissed the technique known as NAND mirroring as unworkable [Article 47722]. - The FBI had considered many different techniques before gaining access to the phone, including the NAND mirroring approach [Article 47722]. (b) The intent of the software failure incident related to accidental_decisions: - Sergei Skorobogatov demonstrated a technique known as NAND mirroring to break into iPhones, which was initially dismissed by the FBI [Article 47722]. - The FBI had paid a third party for software to hack into the iPhone of the San Bernardino gunman [Article 47722]. - The FBI considered various techniques, including NAND mirroring, before gaining access to the phone [Article 47722].
Capability (Incompetence/Accidental) development_incompetence (a) The software failure incident related to development incompetence can be seen in the article where the FBI paid over $1.3 million to unlock the San Bernardino shooter's iPhone 5C, while a computer scientist from Cambridge University demonstrated a technique known as NAND mirroring to break into iPhones up to the iPhone 6. The FBI director initially dismissed this technique as unworkable, but the researcher was able to successfully demonstrate it, showing a gap in the FBI's understanding and potentially highlighting a lack of professional competence in assessing such security vulnerabilities [47722]. (b) The software failure incident related to accidental factors can be observed in the same article where the FBI had initially considered various techniques, including the NAND mirroring approach, but had concluded that it didn't work. However, the researcher from Cambridge University was able to successfully use this technique, indicating that the FBI's assessment may have been accidental or mistaken, leading to a failure in accurately evaluating the security of the iPhone [47722].
Duration permanent (a) The software failure incident in the articles can be considered as a permanent failure. This is evident from the fact that the FBI initially claimed that the technique demonstrated by Sergei Skorobogatov, known as NAND mirroring, was unworkable and did not work for breaking into the iPhone of the San Bernardino shooter. However, Skorobogatov was able to successfully demonstrate the technique and unlock the iPhone, proving the FBI's initial assessment wrong. This indicates a permanent failure in the FBI's understanding and assessment of the security measures related to the iPhone unlocking process [47722].
Behaviour other (a) crash: The software failure incident described in the articles does not involve a crash where the system loses state and does not perform any of its intended functions. The incident is more related to security vulnerabilities and bypassing security measures to gain unauthorized access to the iPhone [47722]. (b) omission: The incident does not involve the system omitting to perform its intended functions at an instance(s). Instead, it focuses on bypassing security measures to unlock the iPhone by exploiting a vulnerability in the password retry attempts mechanism [47722]. (c) timing: The incident is not related to the system performing its intended functions correctly but too late or too early. It is more about circumventing security measures to gain access to the iPhone by manipulating the password retry attempts mechanism [47722]. (d) value: The failure incident is not about the system performing its intended functions incorrectly. It is about finding a way to bypass security measures to unlock the iPhone by resetting the password attempt counter through a hardware-based attack [47722]. (e) byzantine: The incident does not involve the system behaving erroneously with inconsistent responses and interactions. It is more about exploiting a vulnerability in the security mechanism of the iPhone to gain unauthorized access [47722]. (f) other: The behavior of the software failure incident can be categorized as a security vulnerability exploit. It involves using a hardware-based attack to manipulate the password retry attempts mechanism and gain unauthorized access to the iPhone, demonstrating a flaw in the security design of the device [47722].

IoT System Layer

Layer Option Rationale
Perception None None
Communication None None
Application None None

Other Details

Category Option Rationale
Consequence property, non-human, theoretical_consequence, other (a) death: People lost their lives due to the software failure - There is no mention of people losing their lives due to the software failure incident reported in the articles [47722]. (b) harm: People were physically harmed due to the software failure - There is no mention of people being physically harmed due to the software failure incident reported in the articles [47722]. (c) basic: People's access to food or shelter was impacted because of the software failure - There is no mention of people's access to food or shelter being impacted due to the software failure incident reported in the articles [47722]. (d) property: People's material goods, money, or data was impacted due to the software failure - The software failure incident resulted in the FBI paying more than $1.3 million to unlock the San Bernardino shooter's iPhone 5C [47722]. (e) delay: People had to postpone an activity due to the software failure - There is no mention of people having to postpone an activity due to the software failure incident reported in the articles [47722]. (f) non-human: Non-human entities were impacted due to the software failure - The software failure incident involved the hacking of an iPhone, a non-human entity [47722]. (g) no_consequence: There were no real observed consequences of the software failure - The software failure incident had real consequences, such as the FBI paying a significant amount to unlock the iPhone [47722]. (h) theoretical_consequence: There were potential consequences discussed of the software failure that did not occur - Theoretical consequences discussed included the potential impact on encrypted communications and devices if a bill to make it easier to access encrypted communications was passed [47722]. (i) other: Was there consequence(s) of the software failure not described in the (a to h) options? What is the other consequence(s)? - The software failure incident led to a demonstration that a technique dismissed by the FBI director as unworkable was actually successful, highlighting a potential consequence of underestimating certain hacking methods [47722].
Domain information, finance, government (a) The failed system in this incident was related to the information industry, specifically involving the security and encryption of iPhones used by individuals like the San Bernardino shooter [47722]. (h) The incident also has implications for the finance industry, as it involves the FBI paying a significant amount of money to unlock the iPhone of the San Bernardino shooter [47722]. (l) Additionally, the incident is related to the government sector, as it involves the FBI's efforts to access encrypted communications and devices for investigative purposes [47722].

Sources

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