7.1
HIGH
CVE-2019-15794
Ubuntu Overlayfs Refcount Underflow Vulnerability
Description

Overlayfs in the Linux kernel and shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, both replace vma->vm_file in their mmap handlers. On error the original value is not restored, and the reference is put for the file to which vm_file points. On upstream kernels this is not an issue, as no callers dereference vm_file following after call_mmap() returns an error. However, the aufs patchs change mmap_region() to replace the fput() using a local variable with vma_fput(), which will fput() vm_file, leading to a refcount underflow.

INFO

Published Date :

April 24, 2020, 12:15 a.m.

Last Modified :

May 26, 2020, 3:18 p.m.

Remotely Exploitable :

No

Impact Score :

5.2

Exploitability Score :

1.8
Affected Products

The following products are affected by CVE-2019-15794 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
1 Canonical ubuntu_linux
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2019-15794.

URL Resource
https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=270d16ae48a4dbf1c7e25e94cc3e38b4bea37635 Mailing List Patch Third Party Advisory
https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=ef81780548d20a786cc77ed4203fca146fd81ce3 Mailing List Patch Third Party Advisory
https://usn.ubuntu.com/usn/usn-4208-1 Third Party Advisory
https://usn.ubuntu.com/usn/usn-4209-1 Third Party Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2019-15794 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2019-15794 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Reanalysis by [email protected]

    May. 26, 2020

    Action Type Old Value New Value
    Removed CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Added CVSS V3.1 NIST AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
  • Initial Analysis by [email protected]

    May. 01, 2020

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:L/AC:L/Au:N/C:C/I:C/A:C)
    Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Changed Reference Type https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=270d16ae48a4dbf1c7e25e94cc3e38b4bea37635 No Types Assigned https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=270d16ae48a4dbf1c7e25e94cc3e38b4bea37635 Mailing List, Patch, Third Party Advisory
    Changed Reference Type https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=ef81780548d20a786cc77ed4203fca146fd81ce3 No Types Assigned https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=ef81780548d20a786cc77ed4203fca146fd81ce3 Mailing List, Patch, Third Party Advisory
    Changed Reference Type https://usn.ubuntu.com/usn/usn-4208-1 No Types Assigned https://usn.ubuntu.com/usn/usn-4208-1 Third Party Advisory
    Changed Reference Type https://usn.ubuntu.com/usn/usn-4209-1 No Types Assigned https://usn.ubuntu.com/usn/usn-4209-1 Third Party Advisory
    Added CWE NIST CWE-672
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:5.0:*:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:5.3:*:*:*:*:*:*:*
    Added CPE Configuration OR *cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:* *cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2019-15794 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2019-15794 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.05 }} 0.00%

score

0.14285

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
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Scope
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