CVE-2024-35827 – This CVE describes an integer overflow vulnerab... (How to Fix)

Q: What is the severity of CVE-2024-35827?

CVE-2024-35827 has a CVSS score of 5.5 (MEDIUM). This CVE describes an integer overflow vulnerability in the Linux kernel's io_uring subsystem. The flaw occurs when processing network messages, where improper casting could allow an attacker to bypass overflow checks and potentially cause memory corruption. This affects systems running vulnerable Linux kernel versions with io_uring enabled.

📋 TL;DR

This CVE describes an integer overflow vulnerability in the Linux kernel's io_uring subsystem. The flaw occurs when processing network messages, where improper casting could allow an attacker to bypass overflow checks and potentially cause memory corruption. This affects systems running vulnerable Linux kernel versions with io_uring enabled.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific affected versions not explicitly stated in CVE description; check git commits for exact ranges.

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires io_uring subsystem to be enabled and accessible. Some distributions may have io_uring disabled by default.

📦 What is this software?

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel memory corruption leading to privilege escalation, denial of service, or arbitrary code execution in kernel context.

🟠

Likely Case

Kernel panic or system crash causing denial of service.

🟢

If Mitigated

Limited impact if io_uring is disabled or access is restricted to trusted users.

🌐 Internet-Facing: MEDIUM - Requires local access or ability to trigger specific io_uring operations.

🏢 Internal Only: MEDIUM - Local users could potentially exploit this to escalate privileges or crash systems.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires local access and ability to trigger the vulnerable io_recvmsg_mshot_prep() function. No public exploits known at this time.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Check git commits: 0c8c74bb59e7d77554016efc34c2d10376985e5e and related

Vendor Advisory: https://git.kernel.org/stable/c/0c8c74bb59e7d77554016efc34c2d10376985e5e

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution vendor. 2. Reboot system to load new kernel. 3. Verify kernel version after reboot.

🔧 Temporary Workarounds

Disable io_uring

linux

Remove or disable io_uring module if not required

echo 'blacklist io_uring' >> /etc/modprobe.d/blacklist.conf
rmmod io_uring

Restrict io_uring access

linux

Limit which users can access io_uring functionality

chmod 600 /dev/io_uring*
setfacl -m u:root:rw- /dev/io_uring*

🧯 If You Can't Patch

Implement strict access controls to limit which users can use io_uring functionality
Monitor systems for crashes or unusual behavior related to network operations

🔍 How to Verify

Check if Vulnerable:

Check kernel version and compare with patched versions in git commits. Examine if io_uring is loaded: lsmod | grep io_uring

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version after update matches patched version. Check that io_uring module loads without errors.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
System crashes
io_uring related errors in dmesg

Network Indicators:

Unusual io_uring system calls from non-privileged users

SIEM Query:

process.name: 'io_uring' AND event.action: 'system_call' AND user.name NOT IN ('root', 'system')

📊 Metadata

CVE ID: CVE-2024-35827

CVSS v3 Score: 5.5 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CWE: CWE-190

Published: May 17, 2024

Last Updated: February 3, 2025

🔗 References

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🔗 Related Vulnerabilities

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