WolfsshApplication

CVE-2025-11624

CRITICAL · 9.8 CVSS v3.1 Published 2025-10-21
Fix available
A fix is available. Upgrade to after 1.4.20 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

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
Potential stack buffer overwrite on the SFTP server side when receiving a malicious packet that has a handle size larger than the system handle or file descriptor size, but smaller than max handle size allowed.

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 · moderate confidence

Stack buffer overflow vulnerability in SFTP server when processing handle sizes. A malicious packet with handle size exceeding system file descriptor limits but below maximum allowed size can overwrite stack memory, potentially allowing remote code execution.

MitigationApply vendor patch for affected SFTP server software; implement strict bounds validation on handle sizes before buffer operations.

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

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
WolfsshApplication
Affected:>= 1.3.0, <= 1.4.20

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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. Identify Wolfssh installation and version
    Run 'wolfssl -version' or check package manager for wolfssh package version (e.g., dpkg -l | grep -i wolf, rpm -qa | grep -i wolf)
    Affected if Version is between 1.3.0 and 1.4.20 inclusive
  2. Confirm SFTP server component is in use
    Check running processes or service configuration for sftp-server, scp, or wolfssl/wolfssh SFTP daemon instances
    Affected if Wolfssh SFTP server is running or configured as a system service
  3. Verify SFTP handle processing is enabled
    Inspect SFTP server configuration files or logs to confirm handle creation/processing functionality is active (look for subsystem sftp or similar directives)
    Affected if SFTP subsystem or server is enabled and accepting connections
  4. Check for handle size limits in configuration
    Review SFTP server configuration for max handle size or buffer size settings; examine if explicit bounds validation exists
    Affected if No explicit handle size limits are configured or validation is absent

You are affected if Wolfssh version 1.3.0 through 1.4.20 is installed and the SFTP server component is actively processing file handles.

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.

dbcve · scoped
Upgrade available Upgrade to a release after 1.4.20
Vendor patch github.com →
Interim mitigation

Apply vendor patch for affected SFTP server software; implement strict bounds validation on handle sizes before buffer operations.

Recommended fix Moderate confidence

Wolfssh >= 1.4.21

  1. 1. Identify all systems running Wolfssh versions between 1.3.0 and 1.4.20 that expose SFTP server functionality
  2. 2. Review the wolfSSL/wolfssh repository pull request #834 for details on the specific code changes
  3. 3. Update Wolfssh to version 1.4.21 or later which contains the fix for CVE-2025-11624
  4. 4. After upgrading, verify SFTP server functionality remains operational
  5. 5. Test with malformed SFTP packets to confirm the vulnerability is mitigated (in a test environment)

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Wolfssh Scoped from the published advisory
  • Consultation6.0 h
  • Implementation12.0 h
  • Testing10.0 h
  • Review / QA4.0 h
32.0 hours of engineering $5,580
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,928.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-11624 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2025-11624 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
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data