The KEYS subsystem in the Linux kernel before 4.14.6 omitted an access-control check when adding a key to the current task's "default request-key keyring" via the request_key() system call, allowing a local user to use a sequence of crafted system calls to add keys to a keyring with only Search permission (not Write permission) to that keyring, related to construct_get_dest_keyring() in security/keys/request_key.c.
http://www.securityfocus.com/bid/102301
https://github.com/torvalds/linux/commit/4dca6ea1d9432052afb06baf2e3ae78188a4410b
https://lists.debian.org/debian-lts-announce/2018/01/msg00004.html
https://usn.ubuntu.com/3617-1/
https://usn.ubuntu.com/3617-2/
https://usn.ubuntu.com/3617-3/
https://usn.ubuntu.com/3619-1/
https://usn.ubuntu.com/3619-2/
https://usn.ubuntu.com/3620-1/
https://usn.ubuntu.com/3620-2/
https://usn.ubuntu.com/3632-1/
https://www.debian.org/security/2017/dsa-4073
https://www.debian.org/security/2018/dsa-4082
https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.6
Source: MITRE
Published: 2017-12-20
Updated: 2019-10-03
Type: CWE-862
Base Score: 2.1
Vector: AV:L/AC:L/Au:N/C:N/I:P/A:N
Impact Score: 2.9
Exploitability Score: 3.9
Severity: LOW
Base Score: 3.3
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Impact Score: 1.4
Exploitability Score: 1.8
Severity: LOW