CVE-2025-37780

Q: What is the severity of CVE-2025-37780?

CVE-2025-37780 has a CVSS score of 7.1 (HIGH). A memory corruption vulnerability in the Linux kernel's ISO filesystem (isofs) export functionality allows out-of-bounds read access when processing file handles with insufficient buffer size. This affects Linux systems with ISO filesystems mounted and export support enabled. Attackers could potentially read kernel memory or cause denial of service.

7.1 HIGH

📋 TL;DR

A memory corruption vulnerability in the Linux kernel's ISO filesystem (isofs) export functionality allows out-of-bounds read access when processing file handles with insufficient buffer size. This affects Linux systems with ISO filesystems mounted and export support enabled. Attackers could potentially read kernel memory or cause denial of service.

💻 Affected Systems

Products:

Linux kernel

Versions: Kernel versions before fixes (specific versions in git commits provided)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable when ISO filesystem is mounted with export support (nfsd/exportfs). Most desktop systems not affected by default.

📦 What is this software?

Debian Linux by Debian

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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 memory disclosure leading to information leakage, privilege escalation, or system crash/panic.

🟠

Likely Case

Kernel panic or system crash causing denial of service.

🟢

If Mitigated

Minimal impact if ISO export functionality is disabled or systems are not processing malicious file handles.

🌐 Internet-Facing: LOW - Requires local access or specific file handle manipulation; not directly network exploitable.

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

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: NO

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires local access and ability to create/manipulate file handles. Syzbot found via fuzzing.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions with commits: 007124c896e7d4614ac1f6bd4dedb975c35a2a8e, 0405d4b63d082861f4eaff9d39c78ee9dc34f845, 0fdafdaef796816a9ed0fd7ac812932d569d9beb, 56dfffea9fd3be0b3795a9ca6401e133a8427e0b, 5e7de55602c61c8ff28db075cc49c8dd6989d7e0

Vendor Advisory: https://git.kernel.org/stable/c/007124c896e7d4614ac1f6bd4dedb975c35a2a8e

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version from your distribution. 2. Reboot system. 3. Verify kernel version matches patched release.

🔧 Temporary Workarounds

Disable ISO export support

linux

Prevent mounting ISO filesystems with export support to eliminate attack surface

# Ensure no ISO mounts with export options
# Check /etc/fstab and mount commands for 'nfs' or 'export' options with iso9660

🧯 If You Can't Patch

Restrict access to systems to prevent local exploitation
Monitor for crash logs related to isofs_fh_to_parent or KASAN reports

🔍 How to Verify

Check if Vulnerable:

Check kernel version and if ISO filesystems are mounted with export support: 'mount | grep iso9660' and 'cat /proc/filesystems | grep iso9660'

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version includes fix commits: 'uname -r' and check with distribution's security advisory

📡 Detection & Monitoring

Log Indicators:

Kernel panic logs
KASAN reports mentioning isofs_fh_to_parent
slab-out-of-bounds errors in dmesg

Network Indicators:

N/A - local vulnerability

SIEM Query:

Search for: 'isofs_fh_to_parent' OR 'slab-out-of-bounds' OR 'KASAN: slab-out-of-bounds' in kernel logs

📊 Metadata

CVE ID: CVE-2025-37780

CVSS v3 Score: 7.1 (HIGH)

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

CWE: CWE-125

EPSS Score: 0.02% exploit probability (4.6th percentile)

Published: May 1, 2025

Last Updated: November 6, 2025

🔗 References

https://git.kernel.org/stable/c/007124c896e7d4614ac1f6bd4dedb975c35a2a8e Patch
https://git.kernel.org/stable/c/0405d4b63d082861f4eaff9d39c78ee9dc34f845 Patch
https://git.kernel.org/stable/c/0fdafdaef796816a9ed0fd7ac812932d569d9beb Patch
https://git.kernel.org/stable/c/56dfffea9fd3be0b3795a9ca6401e133a8427e0b Patch
https://git.kernel.org/stable/c/5e7de55602c61c8ff28db075cc49c8dd6989d7e0 Patch
https://git.kernel.org/stable/c/63d5a3e207bf315a32c7d16de6c89753a759f95a Patch
https://git.kernel.org/stable/c/952e7a7e317f126d0a2b879fc531b716932d5ffa Patch
https://git.kernel.org/stable/c/ee01a309ebf598be1ff8174901ed6e91619f1749 Patch
https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html Mailing List,Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html Mailing List,Third Party Advisory

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Debian Linux by Debian

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

Disable ISO export support

🧯 If You Can't Patch

🔍 How to Verify

Check if Vulnerable:

Check Version:

Verify Fix Applied:

📡 Detection & Monitoring

Log Indicators:

Network Indicators:

SIEM Query:

📊 Metadata

🔗 References

📤 Share & Export

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