CVE-2015-3306
CriticalExploitedPublic exploitThe 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.
Published May 18, 2015 · Updated Oct 9, 2026 · Also known as DEBIAN-CVE-2015-3306, DSA-3263-1, UBUNTU-CVE-2015-3306
Key Facts
Patch immediately- CVE-2015-3306 is a critical-severity vulnerability (CVSS 10.0 v3.1) affecting Proftpd, Debian Linux, Fedora (Fedoraproject) and 11 more products.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 8, 2026. Public exploit code is available.
- EPSS estimates a 99% probability of exploitation in the next 30 days.
- Fixed versions are available, including Proftpd 1.3.5b-2.5, proftpd-devel 1.3.5b-2.5, proftpd-dfsg 1.3.4a-5+deb7u3.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
10.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
99%
Higher than 99.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2015-3306 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Oct 8, 2026 | Oct 11, 2026 | Not reported |
| Industry KEV feed | Oct 8, 2026 | Oct 11, 2026 | Not reported |
| CIRCL KEV | Oct 8, 2026 | Oct 11, 2026 | Not reported |
| ENISA EUVD | Oct 8, 2026 | n/a | Not reported |
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Affected Products
31 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| ProftpdProftpd | 1.3.5 | 1.3.5b-2.5 |
| Debian LinuxDebian | 7.0, 8.0, 9.0 | n/a |
| FedoraFedoraproject | 20, 21, 22 | n/a |
| TumbleweedOpensuse | See advisory | n/a |
| Linux Enterprise ServerSuse | 15-sp7 | n/a |
Patched Releases
Proftpd
1.3.5b-2.5
proftpd-devel
1.3.5b-2.5
proftpd-dfsg
1.3.4a-5+deb7u3, 1.3.5-1.1+deb8u1, 1.3.5-2, 1.3.5~rc3-2.1ubuntu2.1
proftpd-doc
1.3.5b-2.5
proftpd-lang
1.3.5b-2.5
proftpd-ldap
1.3.5b-2.5
proftpd-mysql
1.3.5b-2.5
proftpd-pgsql
1.3.5b-2.5
proftpd-radius
1.3.5b-2.5
proftpd-sqlite
1.3.5b-2.5
Timeline
Publicly disclosed
May 18, 2015
Added to CISA KEV
Oct 8, 2026
Added to Industry KEV feed
Oct 8, 2026
Added to CIRCL KEV
Oct 8, 2026
Added to ENISA EUVD
Oct 8, 2026
Last updated
Oct 9, 2026
Weakness Type
- CWE-284 Improper Access Control
References
- advisoryhttps://cxsecurity.com/issue/WLB-2015040075
- advisoryhttps://security-tracker.debian.org/tracker/CVE-2015-3306
- advisoryhttps://ubuntu.com/security/CVE-2015-3306
- advisoryhttps://www.cve.org/CVERecord?id=CVE-2015-3306
- advisoryhttp://www.openwall.com/lists/oss-security/2015/04/15/2
FAQ
Common Questions.
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.
Affected: Proftpd versions 1.3.5; Debian Linux versions 7.0, 8.0, 9.0; Fedora (Fedoraproject) versions 20, 21, 22, among others. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Oct 8, 2026.
Yes. It was added on Oct 8, 2026 with a federal remediation due date of Oct 11, 2026.
Public exploit code is available.
Fixed versions are available, including Proftpd 1.3.5b-2.5, proftpd-devel 1.3.5b-2.5, proftpd-dfsg 1.3.4a-5+deb7u3.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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