Security restrictions bypass in Linux kernel - CVE-2017-17807
Published: December 26, 2017
Vulnerability identifier: #VU9777
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2017-17807
CWE-ID: CWE-20
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local attacker to bypass security restrictions on the target system.
The weakness exists due to the KEYS subsystem in the Linux kernel omitted an access-control check when adding a key to the current task's "default request-key keyring" via the request_key() system call. A local attacker can 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 and bypass intended security restrictions.
The weakness exists due to the KEYS subsystem in the Linux kernel omitted an access-control check when adding a key to the current task's "default request-key keyring" via the request_key() system call. A local attacker can 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 and bypass intended security restrictions.
Affected software
Linux kernel
Debian Linux
Debian Linux
How to mitigate CVE-2017-17807
Update to version 4.14.6.