#VU31115 Race condition in Linux kernel


Published: 2019-04-12 | Updated: 2020-07-17

Vulnerability identifier: #VU31115

Vulnerability risk: Low

CVSSv3.1: 4.1 [CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-11190

CWE-ID: CWE-362

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description

The vulnerability allows a local authenticated user to gain access to sensitive information.

The Linux kernel before 4.8 allows local users to bypass ASLR on setuid programs (such as /bin/su) because install_exec_creds() is called too late in load_elf_binary() in fs/binfmt_elf.c, and thus the ptrace_may_access() check has a race condition when reading /proc/pid/stat.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Linux kernel: 4.0 - 4.0.9, 4.1 - 4.1.52, 4.2 - 4.2.8, 4.3 - 4.3.6, 4.4 - 4.4.224, 4.5 - 4.5.7, 4.6 - 4.6.7, 4.7 - 4.7.10


External links
http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00039.html
http://www.openwall.com/lists/oss-security/2019/04/15/1
http://www.securityfocus.com/bid/107890
http://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/commit/?id=a5b5352558f6808db0589644ea5401b3e3148a0d
http://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/commit/?id=e1676b55d874a43646e8b2c46d87f2f3e45516ff
http://lists.debian.org/debian-lts-announce/2019/05/msg00041.html
http://lists.debian.org/debian-lts-announce/2019/05/msg00042.html
http://usn.ubuntu.com/4008-1/
http://usn.ubuntu.com/4008-2/
http://usn.ubuntu.com/4008-3/
http://www.openwall.com/lists/oss-security/2019/04/03/4
http://www.openwall.com/lists/oss-security/2019/04/03/4/1


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.


Latest bulletins with this vulnerability