Apple macOS/iOS – NSUnarchiver Heap Corruption Due to Lack of Bounds Checking in [NSBuiltinCharacterSet initWithCoder:]
Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1170 Via NSUnarchiver we can read NSBuiltinCharacterSet with a controlled serialized state. It reads a controlled int using decodeValueOfObjCType:"i" then either passes it to CFCharacterSetGetPredefined or uses it directly to manipulate __NSBuiltinSetTable. Neither path has any bounds checking and the index is used to maniupulate c arrays of pointers. Attached python script will generate a serialized NSBuiltinCharacterSet with a value of 42 for the character set identifier. tested on MacOS 10.12.3 (16D32) Proof of Concept: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/42050.zip |