CVE-2020-9883: Apple macOS CoreGraphics JBIG2Stream Out-Of-Bounds Read Information Disclosure Vulnerability

CoreGraphics. An out-of-bounds write was addressed with improved input validation.

A buffer overflow issue was addressed with improved memory handling. This issue is fixed in iOS 13.6 and iPadOS 13.6, macOS Catalina 10.15.6, tvOS 13.4.8, watchOS 6.2.8, iTunes 12.10.8 for Windows, iCloud for Windows 11.3, iCloud for Windows 7.20. Processing a maliciously crafted image may lead to arbitrary code execution.

This vulnerability allows remote attackers to disclose sensitive information on affected installations of Apple macOS. Interaction with the CoreGraphics library is required to exploit this vulnerability but attack vectors may vary depending on the implementation. The specific flaw exists within the JBIG2Stream::readGenericBitmap method. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated data structure. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of the current process.