Use-after-free in Linux Kernel modify_ldt()

Published: 2019-07-10 | Updated: 2019-07-10
Severity Low
Patch available YES
Number of vulnerabilities 1
CVE ID CVE-2019-13233
CWE ID CWE-416
Exploitation vector Local
Public exploit N/A
Vulnerable software Linux kernel Subscribe
Vendor Linux Foundation

Security Advisory

This security advisory describes one low risk vulnerability.

1) Use-after-free

Severity: Low

CVSSv3: 7.7 [CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C] [PCI]

CVE-ID: CVE-2019-13233

CWE-ID: CWE-416 - Use After Free

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error within the arch/x86/lib/insn-eval.c file due to a race condition between modify_ldt() and a #BR exception for an MPX bounds violation when accessing LDT entry. A local user can create a specially crafted application and escalate privileges on the system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Linux kernel: 5.1.1, 5.1.2, 5.1.3, 5.1.4, 5.1.5, 5.1.6, 5.1.7, 5.1.8

CPE External links

https://bugs.chromium.org/p/project-zero/issues/detail?id=1879
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.1.9
https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=de9f869616dd95e95c00bdd6b0fcd3421e8a4323
https://github.com/torvalds/linux/commit/de9f869616dd95e95c00bdd6b0fcd3421e8a4323

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.