CVE-2015-8660: High severity linux kernel vulnerability

Q: Who can exploit this issue?

Exploitation requires local access and high privileges. The vulnerable code path is in overlayfs, so systems that do not use overlayfs are not exposed through this flaw.

Q: What can an attacker do?

A local attacker can use a crafted application to bypass intended filesystem permission restrictions during overlayfs initial copy_up and modify attributes of arbitrary overlay files. The CVSS vector indicates impacts to confidentiality, integrity, and availability.

Q: Which kernel versions are affected?

The issue affects Linux kernel versions through 4.3.3. It was fixed in kernel 4.4-rc4.

Published Dec 14, 2015

Updated

A security issue was fixed in kernel 4.4-rc4 resolving the bypassing of filesystem permission checks in overlayfs during the initial copyup.

Upstream patch:

https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=acff81ec2c79492b180fade3c2894425cd35a545

Other sources

The ovlsetattr function in fs/overlayfs/inode.c in the Linux kernel through 4.3.3 attempts to merge distinct setattr operations, which allows local users to bypass intended access restrictions and modify the attributes of arbitrary overlay files via a crafted application.

— MITRE

Affected Software

3 affected components

Linux Linux kernel>=3.18<3.18.31

Linux Linux kernel>=3.19<4.1.22

Linux Linux kernel>=4.2<4.4

Event History

Dec 14, 2015

Data Sourced

03:07 PM

DescriptionSeverityAffected Software

Dec 28, 2015

CVE Published

via MITRE·11:00 AM

Data Sourced

via MITRE·11:00 AM

Description

Frequently Asked Questions

Who can exploit this issue?

Exploitation requires local access and high privileges. The vulnerable code path is in overlayfs, so systems that do not use overlayfs are not exposed through this flaw.

What can an attacker do?

A local attacker can use a crafted application to bypass intended filesystem permission restrictions during overlayfs initial copy_up and modify attributes of arbitrary overlay files. The CVSS vector indicates impacts to confidentiality, integrity, and availability.

Which kernel versions are affected?

The issue affects Linux kernel versions through 4.3.3. It was fixed in kernel 4.4-rc4.

CVE-2015-8660: High severity linux kernel vulnerability

Other sources

Affected Software

Event History

Frequently Asked Questions

Who can exploit this issue?

What can an attacker do?

Which kernel versions are affected?

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Frequently Asked Questions

Who can exploit this issue?

What can an attacker do?

Which kernel versions are affected?