Multiple issues in ld64 in the Xcode toolchains were addressed by updating to version ld64-507.4. This issue is fixed in Xcode 11.0. Compiling code without proper input validation could lead to arbitrary code execution with user privilege.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-8721
Reference (s):
- https://support.apple.com/HT210609