Privilege escalation in Linux Kernel

1) Use-after-free error

EUVDB-ID: #VU14592

Risk: Low

CVSSv3.1: 6.8 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2018-14619

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

The vulnerability allows a local attacker to gain elevated privileges on the target system.

The vulnerability exists in the crypto subsystem of the Linux Kerneldue to incorrect reference to the null skcipher held by each transformation object (TFM), improperly placed when each af_alg_ctx is freed from an affected device. A local attacker can use a custom program, cause the null skcipher to be freed while it is still in use and gain elevated privileges on an affected device.

Mitigation

Update to version 4.15-rc4.

Vulnerable software versions

Linux kernel: 4.4.149 - 4.15 rc3

External links

http://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-14619
http://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b32a7dc8aef1882fbf983e...

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.