PT-2019-4753 · Linux+1 · Linux Kernel+1

Jann Horn · Published 2019-11-01 · Updated 2020-05-01 · CVE-2019-15791

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel versions 5.0 and 5.3

Description The issue is related to an uncontrolled resource consumption in the shiftfs component of the Linux kernel. Exploitation of this issue may allow an attacker to cause a denial of service. The problem arises from the shiftfs btrfs ioctl fd replace() function, which installs an fd referencing a file from the lower filesystem without taking an additional reference to that file, leading to a refcount underflow after the btrfs ioctl completes and the fd is closed.

Recommendations For Linux kernel versions 5.0 and 5.3, consider disabling the shiftfs btrfs ioctl fd replace() function as a temporary workaround until a patch is available. Restrict access to the shiftfs component to minimize the risk of exploitation. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Resource Exhaustion

Integer Underflow

Weakness Enumeration

CWE-672

CWE-400

CWE-191

Related Identifiers

BDU:2020-01325

CVE-2019-15791

USN-4183-1

USN-4184-1

Affected Products

Linux Kernel

Ubuntu

References · 31

• 🔥 https://exploit-db.com/exploits/47693 · Exploit
• https://ubuntu.com/security/CVE-2019-15793 · Vendor Advisory
• https://ubuntu.com/security/CVE-2019-11135 · Vendor Advisory
• https://ubuntu.com/security/CVE-2018-12207 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2019-15791 · Security Note
• https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=601a64857b3d7040ca15c39c929e6b9db3373ec1 · Patch
• https://ubuntu.com/security/CVE-2019-15098 · Vendor Advisory
• https://wiki.astralinux.ru/astra-linux-se81-bulletin-20241206SE81 · Vendor Advisory
• https://osv.dev/vulnerability/USN-4184-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2019-15791 · Security Note
• https://ubuntu.com/security/CVE-2019-17054 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2019-15791 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2019-15791 · Vendor Advisory
• https://ubuntu.com/security/CVE-2019-17053 · Vendor Advisory
• https://ubuntu.com/security/notices/USN-4184-1 · Vendor Advisory