Key insights

• ⚠️ WannaCry, a worldwide cyber attack, encrypted data and demanded ransom payments
• ⚔️ EternalBlue exploit, developed by the NSA, was used in several severe cyber attacks
• 🔓 The exploit chain leverages three different underlying bugs, running entirely within the SMB process on the target machine, making it difficult to detect
• 💸 EternalBlue exploits a bug in casting OS2 fees to NT fees, causing buffer overflow
• 📉 Serve os2 fist size to NT function calculates size and handles specific edge case, bug lies in mismatch between size treatment of 4-byte dword and 2-byte word
• 🔍 Specially crafted packet triggers out-of-bounds write and injects arbitrary data, Bugs A and B synergize to manipulate SMB commands and transaction types
• 🔒 Various protection and mitigation techniques, such as address space layout randomization and data execution prevention, exist to prevent attackers from exploiting buffer overflows
• 🌟 Introduction to the sponsor, Brilliant, offering free access for 30 days and a 20% discount on an annual premium subscription

Q&A

• What does the video highlight about learning and the sponsor, Brilliant?

  The video emphasizes the benefits of hands-on learning experiences and introduces Brilliant as a learning platform offering interactive lessons in math, programming, computer science, data science, and AI. These lessons are designed to instill proper principles, teach fundamentals, and build critical thinking skills through problem-solving. Brilliant also offers free access for 30 days and a 20% discount on an annual premium subscription.

• What are the strategies for protecting against buffer overflows?

  There are various protection and mitigation techniques, such as address space layout randomization and data execution prevention, to prevent attackers from exploiting buffer overflows and their potential impact.

• How does a specially crafted packet contribute to the exploit?

  A specially crafted packet can trigger an out-of-bounds write and inject arbitrary data, achieving this by manipulating SMB commands and transaction types with the help of two bugs, A and B.

• What specific bug does the serve os2 fist size to NT function have?

  The serve os2 fist size to NT function has a bug related to a mismatch between the size treatment of 4-byte dword and 2-byte word, which can lead to potential damage during the casting process.

• How does the EternalBlue exploit work?

  The EternalBlue exploit exploits a bug in casting OS2 fees to NT fees, causing a buffer overflow in the kernel pool. It involves the conversion from OS2 fees to NT fees, determining size, allocating a buffer, and adding individual fees.

• What is the EternalBlue exploit and how was it used?

  The EternalBlue exploit, part of a collection targeting Microsoft's SMB v1 protocol, was made public by The Shadow Brokers after being stolen from the NSA. It was leveraged in the widespread WannaCry attack, using three different bugs within the SMB process, making it difficult to detect.

• What is W cry and what damage did it cause?

  W cry is a worldwide cyber attack that rapidly spread in 2017, encrypting data and causing billions in damages. It affected 230,000 computers and led to accusations against North Korea and Russia for involvement in the attacks.

• 00:00 A cyber attack known as W cry, caused by the EternalBlue exploit, spread rapidly in 2017, encrypting data and causing billions in damages. It led to accusations against North Korea and Russia.
• 03:38 The EternalBlue exploit was part of a collection of exploits targeting Microsoft's SMB v1 protocol and was made public by The Shadow Brokers after being stolen from the NSA, leading to the widespread WannaCry attack. The exploit chain leverages three different underlying bugs, running entirely within the SMB process on the target machine, making it difficult to detect.
• 06:58 When dealing with file operations, extended file attributes or fees are used to store metadata associated with a file. The wrong casting bug in EternalBlue exploits a casting operation from OS2 fees to NT fees, causing a buffer overflow in the non-paged kernel pool. OS2 fees and NT fees have different data structures, and a function is used to convert OS2 fees to NT fees by determining the appropriate size, allocating a buffer, and adding the individual fees.
• 10:12 The serve os2 fist size to NT function calculates the size needed for the NT fist and handles a specific edge case with overflowing fees by shrinking the size of list in bytes. The bug lies in the mismatch between the size treatment of 4-byte dword and 2-byte word which can cause the size of list in bytes to be enlarged instead of shrunk, leading to potential damage during the casting process.
• 13:15 A specially crafted packet can trigger an out-of-bounds write and inject arbitrary data past the boundary of the NT buffer in the kernel pool. Two bugs, A and B, work together to achieve this by manipulating SMB commands and transaction types.
• 16:34 Buffer overflows and their potential impact are discussed, along with strategies for protection. The video also highlights the benefits of learning through hands-on experiences and introduces the sponsor, Brilliant, as a learning platform.