SB2019071014 - Use-after-free in Linux Kernel modify_ldt()
Published: July 10, 2019
Security Bulletin ID
SB2019071014
Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 security vulnerability.
1) Use-after-free (CVE-ID: CVE-2019-13233)
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.
Remediation
Install update from vendor's website.
References
- 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