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ProftpdApplication

CVE-2015-3306

HIGH · 10.0 CVSS v2.0 Published 2015-05-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
High EPSS Public exploit Remotely reachable No privileges 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
The mod_copy module in ProFTPD 1.3.5 allows remote attackers to read and write to arbitrary files via the site cpfr and site cpto commands.

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

The mod_copy module in ProFTPD 1.3.5 contains a critical vulnerability allowing unauthenticated remote attackers to read and write arbitrary files on the server by abusing the SITE CPFR (copy from) and SITE CPTO (copy to) commands. Attackers can leverage this to read sensitive files (like /etc/passwd) or write files to achieve remote code execution.

MitigationUpgrade ProFTPD to version 1.3.5d or later which patches this vulnerability. If upgrading is not immediately feasible, disable the mod_copy module or restrict access to SITE commands in the configuration. Additionally, network-level filtering to limit FTP access to trusted IPs can reduce exposure.

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
ProftpdApplication
Affected:= 1.3.5

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
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete

AV:N/AC:L/Au:N/C:C/I:C/A:C

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 ProFTPD version
    Run 'proftpd -v' or check the package version with 'rpm -q proftpd' (RHEL) or 'dpkg -l proftpd' (Debian)
    Affected if The installed version is exactly 1.3.5 (not 1.3.5d or later)
  2. Verify mod_copy module is loaded
    Check the ProFTPD configuration file (typically /etc/proftpd.conf or /etc/proftpd/modules.conf) for 'LoadModule mod_copy.c' or check if mod_copy is listed in the modules being loaded
    Affected if mod_copy module is explicitly loaded in the configuration and the server is running 1.3.5
  3. Confirm SITE command availability
    Attempt an FTP connection to the server (even anonymously) and issue 'SITE HELP' or 'SITE CPFR /etc/passwd' to see if these commands are accepted
    Affected if The server responds to SITE commands without requiring authentication
  4. Test for unrestricted file access
    Connect to the FTP service and try 'SITE CPFR /etc/passwd' followed by 'SITE CPTO /tmp/test_copy' to verify if arbitrary file reading/writing is possible
    Affected if The server allows copying files from protected locations without authentication

The environment is affected if running ProFTPD version 1.3.5 with mod_copy module enabled and SITE commands are accessible without authentication.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade ProFTPD to version 1.3.5d or later which patches this vulnerability. If upgrading is not immediately feasible, disable the mod_copy module or restrict access to SITE commands in the configuration. Additionally, network-level filtering to limit FTP access to trusted IPs can reduce exposure.

Recommended fix High confidence

ProFTPD 1.3.5a or later (1.3.6 recommended)

  1. 1. Identify the current ProFTPD version running on the system (e.g., proftpd -v or rpm -q proftpd)
  2. 2. Upgrade to ProFTPD 1.3.5a or later (1.3.6 recommended) using the system's package manager (e.g., yum update proftpd or dnf update proftpd)
  3. 3. After upgrading, verify the new version is installed: proftpd -v
  4. 4. Restart the ProFTPD service to load the updated binaries
  5. 5. Confirm the mod_copy vulnerability is patched by checking release notes or testing that unauthenticated site cpfr/cpto commands are rejected
  6. Alternative mitigation if upgrade is not immediately possible: Comment out or remove the LoadModule mod_copy.c line in proftpd.conf to disable the vulnerable module, then restart the service
Caveat Minimal - this is a security patch release; ensure any custom mod_copy configurations are reviewed after upgrade

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

Fix this in Proftpd Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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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-2015-3306 in production — separate from our analysis above.

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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
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  • Version or environment caveats, and links to real fixes
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