CVE-2023-52604 – This is an out-of-bounds array access vulnerabi... (How to Fix)

Q: What is the severity of CVE-2023-52604?

CVE-2023-52604 has a CVSS score of 7.8 (HIGH). This is an out-of-bounds array access vulnerability in the JFS filesystem driver in the Linux kernel. An attacker could trigger a kernel panic (denial of service) by exploiting this flaw. Systems using JFS filesystems with affected kernel versions are vulnerable.

📋 TL;DR

This is an out-of-bounds array access vulnerability in the JFS filesystem driver in the Linux kernel. An attacker could trigger a kernel panic (denial of service) by exploiting this flaw. Systems using JFS filesystems with affected kernel versions are vulnerable.

💻 Affected Systems

Products:

Linux kernel

Versions: Kernel versions before fixes in stable trees (specific commits listed in references)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if JFS filesystem is mounted or being used. Many distributions don't enable JFS 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 →

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 panic leading to system crash and denial of service, potentially causing data corruption or loss if filesystem operations are interrupted.

🟠

Likely Case

Local denial of service through kernel panic when specific JFS operations are performed on maliciously crafted filesystems.

🟢

If Mitigated

No impact if JFS filesystem is not mounted or kernel is patched.

🌐 Internet-Facing: LOW - Requires local access or ability to mount JFS filesystems.

🏢 Internal Only: MEDIUM - Local users or processes with JFS access could cause system crashes.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and ability to trigger JFS operations. Syzkaller fuzzer discovered this issue.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in kernel stable trees via commits: 42f433785f108893de0dd5260bafb85d7d51db03, 59342822276f753e49d27ef5eebffbba990572b9, 6a44065dd604972ec1fbcccbdc4a70d266a89cdd, 6fe8b702125aeee6ce83f20092a2341446704e7b, 9862ec7ac1cbc6eb5ee4a045b5d5b8edbb2f7e68

Vendor Advisory: https://git.kernel.org/stable/c/42f433785f108893de0dd5260bafb85d7d51db03

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing the fix. 2. Check your distribution's security advisories for specific patched kernel versions. 3. Reboot system after kernel update.

🔧 Temporary Workarounds

Disable JFS filesystem

linux

Prevent JFS filesystem from being mounted or loaded

echo 'install jfs /bin/false' >> /etc/modprobe.d/disable-jfs.conf
rmmod jfs 2>/dev/null || true
update-initramfs -u

🧯 If You Can't Patch

Avoid using JFS filesystems - use ext4, xfs, or btrfs instead
Restrict local user access to systems with JFS mounts

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if JFS module is loaded: uname -r && lsmod | grep jfs

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is patched and check dmesg for JFS-related warnings

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages in dmesg or system logs
UBSAN: array-index-out-of-bounds errors related to jfs_dmap.c

Network Indicators:

None - local vulnerability

SIEM Query:

source="kernel" AND ("panic" OR "UBSAN" OR "jfs_dmap")

📊 Metadata

CVE ID: CVE-2023-52604

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-129

Published: March 6, 2024

Last Updated: December 12, 2024

🔗 References

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🔗 Related Vulnerabilities

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