tl;dr

• The patch adds a vulnerable virtio device
• The device accesses pointers without bound check
• Abuse OOB pointer access to setup arb r/w primitive
• Craft open,read,write ropchain on heap
• Overwrite virtqueue handler with stack pivoting gadget

Full solution of Batman Investigation II - Gotham Underground Corruption from bi0sctf 2024

tl;dr

• Challenge 2 of Batman Investigation series
• Memory Forensics - WinDBG Dump Debugging - Malware Analysis - Blockchain Forensics - Password Retrieval - MAC Artefact Analysis

tl;dr

• native.c:
  • Reverse engineering matrix operations performed.
• tallocator.c:
  • Exploiting an arbitrary free to corrupt heap metadata.
  • Reverse shellcode to execute an ORW.

tl;dr

• Sanitizing request causes null byte overflow which corrupts type
• Processing corrupted request doesn’t remove it from incoming_queue
• Reaping corrupted request still leaves it in incoming_queue causing UAF
• Setup crosscache to abuse UAF
• UAF provides free primitive through double reset

tl;dr

• Fuzzing to find the /internal endpoint
• Chaining CVE-2023–24329 and the SSRF in the /okay endpoint to access the internal docker registry host.
• Downloading image blobs using the docker registry API.
• Using CVE-2024-21488 to get RCE on the vec service.
• As the templates directory of the core service is cross-mounted, we can modify the index.html file from vec service to get RCE on the core service.
• Hence we can read the flag from the core service.

tl;dr

• Using brainf*ck to search for flag bytes within a huge tape
• 3 levels with varying constraints to leak flag
• Intended as a code golfing challenge

tl;dr

• Capturing the flag id through redos attack in /search endpoint
• XSS in /uuid/noteid/raw and HTML injection in /uuid/noteid
• CSP frame-src bypass through server side redirect

tl;dr

• Adding the last character to a tab causes null byte overflow
• Use said overflow to unset prev_inuse bit
• Coalesce upwards with fake chunk to perform unlink attack
• Unlink attack places .bss pointer in place of heap pointer
• Editing .bss allows for Arbitrary R/W

tl;dr

• Leak JWT token through Race Condition.
• Leak authorization token via an open redirect.
• Chaining XSS & CSRF in the oauth pipeline to leak the Admin’s oauth access token.
• RCE via CVE-2023-33733.