Vulnerability identifier: #VU31093

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-2019-3901

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.

A race condition in perf_event_open() allows local attackers to leak sensitive data from setuid programs. As no relevant locks (in particular the cred_guard_mutex) are held during the ptrace_may_access() call, it is possible for the specified target task to perform an execve() syscall with setuid execution before perf_event_alloc() actually attaches to it, allowing an attacker to bypass the ptrace_may_access() check and the perf_event_exit_task(current) call that is performed in install_exec_creds() during privileged execve() calls. This issue affects kernel versions before 4.8.

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

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External links
http://www.securityfocus.com/bid/89937
http://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3901
http://lists.debian.org/debian-lts-announce/2019/05/msg00041.html
http://lists.debian.org/debian-lts-announce/2019/05/msg00042.html
http://security.netapp.com/advisory/ntap-20190517-0005/

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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.