The critical Linux kernel flaw (CVE-2016-0728) has been identified by a group of researchers at a startup named Perception Point.
The vulnerability has existed since 2012, but was disclosed in January, 2016.
Vulnerable component: Linux kernel
CVSSv3 score: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:F/RL:O/RC:C
CWE-ID: CWE-119 - Improper Restriction of Operations within the Bounds of a Memory Buffer
The vulnerability allows a local attacker to gain elevated privileges on the target system.
The weakness exists due to use-after-free error in the join_session_keyring() function in security/keys/process_keys.c when handling keyring object reference counting by Linux kernel's key management subsystem. A local attacker can overflow the usage field via a specially crafted object and execute arbitrary code with root privileges.
Successful exploitation of the vulnerability may result in arbitrary code execution on the vulnerable system.
Note: the vulnerability was being actively exploited.