A heap out-of-bounds read/write vulnerability in the Linux Kernel traffic control (QoS) subsystem can be exploited to achieve local privilege escalation.
The qfq_change_class function does not properly limit the lmax variable which can lead to out-of-bounds read/write. If the TCA_QFQ_LMAX value is not offered through nlattr, lmax is determined by the MTU value of the network device. The MTU of the loopback device can be set up to 2^31-1 and as a result, it is possible to have an lmax value that exceeds QFQ_MIN_LMAX.
We recommend upgrading past commit 3037933448f60f9acb705997eae62013ecb81e0d.
:heavy_check_mark: This issue was automatically closed by Mend because the vulnerable library in the specific branch(es) was either marked as ignored or it is no longer part of the Mend inventory.
CVE-2023-2248 - High Severity Vulnerability
Vulnerable Library - linux-stable-rtv4.1.33
Julia Cartwright's fork of linux-stable-rt.git
Library home page: https://git.kernel.org/pub/scm/linux/kernel/git/julia/linux-stable-rt.git
Found in base branch: master
Vulnerable Source Files (2)
/net/sched/sch_qfq.c /net/sched/sch_qfq.c
Vulnerability Details
A heap out-of-bounds read/write vulnerability in the Linux Kernel traffic control (QoS) subsystem can be exploited to achieve local privilege escalation. The qfq_change_class function does not properly limit the lmax variable which can lead to out-of-bounds read/write. If the TCA_QFQ_LMAX value is not offered through nlattr, lmax is determined by the MTU value of the network device. The MTU of the loopback device can be set up to 2^31-1 and as a result, it is possible to have an lmax value that exceeds QFQ_MIN_LMAX. We recommend upgrading past commit 3037933448f60f9acb705997eae62013ecb81e0d.
Publish Date: 2023-05-01
URL: CVE-2023-2248
CVSS 3 Score Details (7.8)
Base Score Metrics: - Exploitability Metrics: - Attack Vector: Local - Attack Complexity: Low - Privileges Required: Low - User Interaction: None - Scope: Unchanged - Impact Metrics: - Confidentiality Impact: High - Integrity Impact: High - Availability Impact: High
For more information on CVSS3 Scores, click here.Suggested Fix
Type: Upgrade version
Origin: https://www.linuxkernelcves.com/cves/CVE-2023-2248
Release Date: 2023-05-01
Fix Resolution: v4.14.314,v4.19.282,v5.10.179,v5.15.109,v5.4.242,v6.1.26,v6.2.13
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