CVE-2019-11190

kernel: ASLR bypass for setuid binaries due to late install_exec_creds()

Severity Score

4.7

*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

El kernel de Linux anterior a la versión 4.8 permite a los usuarios locales eludir ASLR en programas setuid (como /bin/su) porque install_exec_creds() es llamado demasiado tarde en load_elf_binary() en fs/binfmt_elf.c, y por lo tanto la comprobación ptrace_may_access() tiene una condición de carrera al leer /proc/pid/stat.

A flaw in the load_elf_binary() function in the Linux kernel allows a local attacker to leak the base address of .text and stack sections for setuid binaries and bypass ASLR because install_exec_creds() is called too late in this function.

USN-4008-1 fixed vulnerabilities in the Linux kernel for Ubuntu 16.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement kernel from Ubuntu 16.04 LTS for Ubuntu 14.04 ESM. Robert Swiecki discovered that the Linux kernel did not properly apply Address Space Layout Randomization in some situations for setuid elf binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid elf binary. Various other issues were also addressed.

*Credits: N/A

CVSS Scores

Attack Vector

Local

Attack Complexity

High

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

Attack Vector

Local

Attack Complexity

Medium

Authentication

None

Confidentiality

Complete

Integrity

None

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2019-04-11 CVE Reserved
2019-04-11 CVE Published
2024-08-04 CVE Updated
2024-08-04 First Exploit
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-250: Execution with Unnecessary Privileges
CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CAPEC

References (14)

URL	Tag	Source
http://www.openwall.com/lists/oss-security/2019/04/15/1	Mailing List
http://www.securityfocus.com/bid/107890	Vdb Entry
https://lists.debian.org/debian-lts-announce/2019/05/msg00041.html	Mailing List
https://lists.debian.org/debian-lts-announce/2019/05/msg00042.html	Mailing List

URL	Date	SRC
https://www.openwall.com/lists/oss-security/2019/04/03/4	2024-08-04
https://www.openwall.com/lists/oss-security/2019/04/03/4/1	2024-08-04

URL	Date	SRC
https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/commit/?id=a5b5352558f6808db0589644ea5401b3e3148a0d	2019-06-07
https://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git/commit/?id=e1676b55d874a43646e8b2c46d87f2f3e45516ff	2019-06-07

URL	Date	SRC
http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00039.html	2019-06-07
https://usn.ubuntu.com/4008-1	2019-06-07
https://usn.ubuntu.com/4008-2	2019-06-07
https://usn.ubuntu.com/4008-3	2019-06-07
https://access.redhat.com/security/cve/CVE-2019-11190	2020-03-31
https://bugzilla.redhat.com/show_bug.cgi?id=1699856	2020-03-31

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 4.8 Search vendor "Linux" for product "Linux Kernel" and version " < 4.8"		-		Affected