CVE-2023-53204

Q: What is the severity of CVE-2023-53204?

CVE-2023-53204 has a CVSS score of 4.7 (MEDIUM). This CVE describes a data race condition in the Linux kernel's AF_UNIX socket implementation where the user->unix_inflight counter is accessed without proper synchronization. This could lead to incorrect file descriptor accounting, potentially causing denial of service or resource exhaustion. Systems running affected Linux kernel versions are vulnerable.

4.7 MEDIUM

📋 TL;DR

This CVE describes a data race condition in the Linux kernel's AF_UNIX socket implementation where the user->unix_inflight counter is accessed without proper synchronization. This could lead to incorrect file descriptor accounting, potentially causing denial of service or resource exhaustion. Systems running affected Linux kernel versions are vulnerable.

💻 Affected Systems

Products:

Linux Kernel

Versions: Specific affected versions not explicitly stated, but references indicate fixes in stable kernel trees. Likely affects multiple 6.x kernel versions.

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ⚠️ Yes

Notes: Requires AF_UNIX socket usage. Systems with heavy UNIX domain socket traffic are more likely to trigger the race condition.

📦 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...

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⚠️ Risk & Real-World Impact

🔴

Worst Case

Kernel panic or system crash due to incorrect resource accounting leading to memory corruption or file descriptor exhaustion.

🟠

Likely Case

System instability, application crashes, or denial of service for processes using UNIX domain sockets.

🟢

If Mitigated

Minor performance impact or occasional application errors if race condition triggers.

🌐 Internet-Facing: LOW - This vulnerability requires local access or ability to execute code on the system.

🏢 Internal Only: MEDIUM - Local users or compromised applications could exploit this to cause system instability.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires triggering the specific race condition between unix_inflight() and too_many_unix_fds() functions, which may be timing-dependent.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions containing commits: 03d133dfbcec9d439729cc64706c7eb6d1663a24, 0bc36c0650b21df36fbec8136add83936eaf0607, 9151ed4b006125cba7c06c79df504340ea4e9386, ac92f239a079678a035c0faad9089354a874aede, adcf4e069358cdee8593663650ea447215a1c49e

Vendor Advisory: https://git.kernel.org/stable/c/03d133dfbcec9d439729cc64706c7eb6d1663a24

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

Limit UNIX socket usage

all

Reduce usage of UNIX domain sockets where possible to minimize exposure to the race condition.

🧯 If You Can't Patch

Monitor system logs for kernel panics or application crashes related to socket operations
Implement strict access controls to limit local user privileges and reduce attack surface

🔍 How to Verify

Check if Vulnerable:

Check if kernel version is affected by examining kernel source for the specific commits or checking distribution security advisories.

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version after update matches patched versions from distribution vendor.

📡 Detection & Monitoring

Log Indicators:

Kernel panic messages
System crash dumps
Application errors related to socket operations or file descriptors

SIEM Query:

source="kernel" AND ("panic" OR "BUG" OR "KCSAN" OR "data-race")

📊 Metadata

CVE ID: CVE-2023-53204

CVSS v3 Score: 4.7 (MEDIUM)

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

CWE: CWE-362

EPSS Score: 0.01% exploit probability (0.6th percentile)

Published: September 15, 2025

Last Updated: December 4, 2025

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

Linux Kernel by Linux

⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Limit UNIX socket usage

🧯 If You Can't Patch

🔍 How to Verify

Check if Vulnerable:

Check Version:

Verify Fix Applied:

📡 Detection & Monitoring

Log Indicators:

SIEM Query:

📊 Metadata

🔗 References

📤 Share & Export

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