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Clash, Burn, and Exploit: Manipulate Filters to Pwn kernelCTF

s the successor to the iptables, nftables stands as a crucial network component within the Linux kernel, managing packet filtering and other network-related functionalities. With continuous development and changes, features designed to increase its efficiency, such as batch commit, anonymous chains/sets, and asynchronous garbage collection, have been implemented, which in turn has significantly increased its complexity and made it an attractive target for attackers in recent years. Since the announcement of the kernelCTF bug bounty, multiple nftables 0-day vulnerabilities have been reported and patched to enhance its security. However, if not careful enough, the security patch may not only mitigate the bug but also introduce new security issues unintentionally. By researching the structural changes in the nftables codebase, we successfully uncover new vulnerabilities despite the intense competition in kernelCTF. Also, we managed to speedrun the exploitation just before Google removed

English
  • Originally Aired August 11, 2024
  • Runtime 45 minutes
  • Created August 25, 2024 by
    Subscriber-2473783
  • Modified August 25, 2024 by
    Subscriber-2473783