In YARA 3.8.1, bytecode in a specially crafted compiled rule can read uninitialized data from VM scratch memory in libyara/exec.c. This can allow attackers to discover addresses in the real stack (not the YARA virtual stack).
In YARA 3.8.1, bytecode in a specially crafted compiled rule can read data from any arbitrary address in memory, in libyara/exec.c. Specifically, OP_COUNT can read a DWORD.
In YARA 3.8.1, bytecode in a specially crafted compiled rule is exposed to information about its environment, in libyara/exec.c. This is a consequence of the design of the YARA virtual machine.
Created yara tracking bugs for this issue:
Affects: epel-all [bug 1660399]
Affects: fedora-all [bug 1660398]
This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.