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CVE-2023-52810

8.4 HIGH

📋 TL;DR

This CVE is an integer underflow vulnerability in the JFS filesystem implementation in the Linux kernel where a negative value for db_l2nbperpage can be used as a shift exponent, causing undefined behavior. This could potentially lead to kernel crashes or privilege escalation. It affects Linux systems using the JFS filesystem.

💻 Affected Systems

Products:
  • Linux kernel
Versions: All versions before fixes in stable kernel releases (specific commits listed in references)
Operating Systems: Linux distributions using affected kernel versions
Default Config Vulnerable: ⚠️ Yes
Notes: Only affects systems with JFS filesystem mounted or accessible. Many distributions don't use 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 →

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 or potential privilege escalation to root via kernel memory corruption.

🟠

Likely Case

System crash or kernel panic when accessing JFS filesystems with malformed metadata.

🟢

If Mitigated

System crash without privilege escalation if kernel hardening features are enabled.

🌐 Internet-Facing: LOW - Requires local filesystem access, not directly network exploitable.
🏢 Internal Only: MEDIUM - Local users could potentially crash systems or escalate privileges if they have JFS filesystem access.

🎯 Exploit Status

Public PoC: ✅ No
Weaponized: UNKNOWN
Unauthenticated Exploit: ✅ No
Complexity: MEDIUM

Requires local access and ability to trigger the JFS code path with malformed parameters. Syzbot found via fuzzing.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Fixed in stable kernel releases via commits: 0cb567e727339a192f9fd0db00781d73a91d15a6, 1a7c53fdea1d189087544d9a606d249e93c4934b, 491085258185ffc4fb91555b0dba895fe7656a45, 524b4f203afcf87accfe387e846f33f916f0c907, 525b861a008143048535011f3816d407940f4bfa

Vendor Advisory: https://git.kernel.org/stable/c/0cb567e727339a192f9fd0db00781d73a91d15a6

Restart Required: Yes

Instructions:

1. Update Linux kernel to version containing fixes. 2. Check distribution security advisories. 3. Reboot system after kernel update.

🔧 Temporary Workarounds

Disable JFS filesystem

linux

Prevent loading JFS kernel module to eliminate attack surface

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

🧯 If You Can't Patch

  • Avoid using JFS filesystems on affected systems
  • Implement strict access controls to limit who can mount or access JFS filesystems

🔍 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 git commit history for fix commits

📡 Detection & Monitoring

Log Indicators:

  • Kernel panic messages
  • UBSAN: shift-out-of-bounds errors in kernel logs
  • JFS-related crash dumps

Network Indicators:

  • None - local vulnerability only

SIEM Query:

source="kernel" AND ("shift-out-of-bounds" OR "UBSAN" OR "jfs_dmap.c:799")

📊 Metadata

CVE ID: CVE-2023-52810
CVSS v3 Score: 8.4 (HIGH)
CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-1335
Published: May 21, 2024
Last Updated: April 2, 2025

🔗 References

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