Linux Kernel: High Severity Advisories for DoS and Privilege Escalation

May 26, 2023 •

2 - 3 min read

Several important security issues have been found in the Linux kernel, which could result in denial of service (DoS) attacks, the exposure of sensitive information, unauthorized execution of management commands, and privilege escalation attacks. With a low attack complexity and a high confidentiality, integrity and availability impact, it is critical that all impacted users update immediately to protect against attacks leading to loss of system access and the compromise of critical systems and confidential data.

The Cybersecurity & Infrastructure Security Agency (CISA) has also added seven new Linux vulnerabilities to its Known Exploited Vulnerabilities (KEV) catalog based on evidence of active exploitation, some of which have been known for a decade. We examine the impact of these flaws and how to find the information you need to protect against them.

Continue reading to learn about other significant issues that have been discovered and fixed in the open-source programs and applications you use.

Yours in Open Source,

Brittany Signature 150 Esm W150

Linux Kernel

The Discovery

Several important security issues have been found in the Linux kernel, including a slab-out-of-bound read problem (CVE-2023-1380), a heap out-of-bounds read/write vulnerability in the traffic control (QoS) subsystem (CVE-2023-2248), and an out-of-bounds write issue in the kernel before 6.2.13 (CVE-2023-31436). The vulnerabilities have received a National Vulnerability Database (NVD) rating of “high-severity” due to their high confidentiality, integrity and availability impact.

The Impact

These issues could result in denial of service (DoS) attacks, the exposure of sensitive information, unauthorized execution of management commands, and privilege escalation attacks.

The Fix

We strongly recommend that all impacted users apply the kernel updates issued by their distro(s) immediately to protect against attacks leading to loss of system access and the compromise of critical systems and confidential data.

Your Related Advisories:

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Ruby

The Discovery

Distros continue to release updates for two important ReDoS issues discovered in Ruby through 3.2.1 (CVE-2023-28755 and CVE-2023-28756). With a low attack complexity and a high availability impact, these vulnerabilities have received a National Vulnerability Database (NVD) base score of 7.5 out of 10 (“High” severity).

The Impact

An attacker could possibly use these issues to cause a denial of service (DoS) resulting in loss of access to critical systems.

The Fix

Important updates for Ruby that fix this dangerous vulnerability have been released. We urge all impacted users to apply the Ruby updates issued by their distro(s) now to protect against attacks leading to loss of access and potential compromise.

Your Related Advisories:

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runC

The Discovery

Several important security issues were identified in the runC Open Container Project. It was discovered that runC incorrectly performed access control when mounting /proc to non-directories (CVE-2023-27561), and incorrectly handled /proc and /sys mounts inside a container (CVE-2023-28642).

The Impact

These bugs could possibly allow an attacker to escalate privileges or bypass AppArmor, and potentially SELinux.

The Fix

A runC security update that fixes these flaws has been released. We strongly recommend that all impacted users apply the runC updates issued by their distro(s) as soon as possible to protect the confidentiality, integrity and availability of their systems.

Your Related Advisories:

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