Stack-based Buffer OverflowWeakness · CWE-121

CVE-2025-0373

MEDIUM · 6.0 CVSS v3.1 Published 2025-01-30
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
66/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
On 64-bit systems, the implementation of VOP_VPTOFH() in the cd9660, tarfs and ext2fs filesystems overflows the destination FID buffer by 4 bytes, a stack buffer overflow. A NFS server that exports a cd9660, tarfs, or ext2fs file system can be made to panic by mounting and accessing the export with an NFS client. Further exploitation (e.g., bypassing file permission checking or remote kernel code execution) is potentially possible, though this has not been demonstrated. In particular, release kernels are compiled with stack protection enabled, and some instances of the overflow are caught by this mechanism, causing a panic.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A 4-byte stack buffer overflow exists in the VOP_VPTOFH() function implementation across cd9660, tarfs, and ext2fs filesystems on 64-bit systems. The FID buffer destination is undersized, causing overflow. An NFS server exporting any of these filesystems can be remotely crashed by a client mounting and accessing the export, and further exploitation for permission bypass or remote code execution is theoretically possible.

MitigationUpdate the kernel to a version that includes the corrected buffer size calculations in VOP_VPTOFH() for the affected filesystems, or disable NFS export of cd9660, tarfs, and ext2fs filesystems as a temporary workaround.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify NFS server is running
    Run 'ps aux | grep nfsd' or 'systemctl status nfs-server' to check if the NFS daemon is active
    Affected if NFS server is not running (not affected); if running, proceed to next checks
  2. List NFS exports
    Run 'showmount -e localhost' or check /etc/exports to see what filesystems are being exported
    Affected if cd9660, tarfs, or ext2fs filesystems appear in the export list
  3. Check mounted filesystems of affected types
    Run 'mount | grep -E "cd9660|tarfs|ext2fs"' or check /proc/mounts for these filesystem types
    Affected if Any of these filesystems are currently mounted on the system
  4. Confirm 64-bit architecture
    Run 'uname -m' or 'getconf LONG_BIT' - the vulnerability only affects 64-bit systems
    Affected if System is 64-bit (x86_64, aarch64, etc.) and meets other conditions
  5. Compare kernel version to fixed releases
    Run 'uname -r' to get the kernel version, then compare against the version that includes the VOP_VPTOFH() fix for your OS distribution
    Affected if Kernel version predates the security fix for this buffer overflow

A system is affected if it runs a 64-bit kernel with NFS server enabled and exports or has mounted cd9660, tarfs, or ext2fs filesystems, and the kernel version is older than the patched release.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update the kernel to a version that includes the corrected buffer size calculations in VOP_VPTOFH() for the affected filesystems, or disable NFS export of cd9660, tarfs, and ext2fs filesystems as a temporary workaround.

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,920
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Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-0373 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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