Race condition in Linux kernel - CVE-2019-3901

 

Race condition in Linux kernel - CVE-2019-3901

Published: April 22, 2019 / Updated: July 17, 2020


Vulnerability identifier: #VU31093
CSH Severity: Low
CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2019-3901
CWE-ID: CWE-362
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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.


Affected software

Linux kernel
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, big endian - Extended Update Support
Red Hat Enterprise Linux EUS Compute Node
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux Server - TUS
Red Hat Virtualization Host - Extended Update Support 4.2 for RHEL
kernel (Red Hat package)

How to mitigate CVE-2019-3901

Install update from vendor's website.

Linux kernel - update to 4.8
kernel (Red Hat package) - update to 3.10.0-957.56.1.el7

External References

Related Security Bulletins