HOMEVULNERABILITIESCVE-2009-3639
MEDIUM

CVE-2009-3639

CWE-310Published: October 28, 2009· Updated: Jun 16, 2026

5.8
CVSS v3.1

Official Description

The mod_tls module in ProFTPD before 1.3.2b, and 1.3.3 before 1.3.3rc2, when the dNSNameRequired TLS option is enabled, does not properly handle a '\0' character in a domain name in the Subject Alternative Name field of an X.509 client certificate, which allows remote attackers to bypass intended client-hostname restrictions via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

NVD Source

Technical Analysis

CVE-2009-3639 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityM
Privileges Req.
User Interaction
Scope
Impact
ConfidentialityNone
IntegrityP
AvailabilityP
AV:N/AC:M/Au:N/C:N/I:P/A:P

Affected Vendors & Products

proftpd1 product(s)
proftpd
Source: NVD CPE · 4 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttp://www.securityfocus.com/bid/36804
PATCHhttps://bugzilla.redhat.com/show_bug.cgi?id=530719
PATCHhttp://www.securityfocus.com/bid/36804
PATCHhttps://bugzilla.redhat.com/show_bug.cgi?id=530719
ADVISORYhttp://secunia.com/advisories/37131
ADVISORYhttp://secunia.com/advisories/37131

All References (24)

→
http://bugs.proftpd.org/show_bug.cgi?id=3275
→
http://marc.info/?l=oss-security&m=125630966510672&w=2
→
http://marc.info/?l=oss-security&m=125632960508211&w=2
→
http://secunia.com/advisories/37131Vendor Advisory
→
http://secunia.com/advisories/37219
→
http://www.debian.org/security/2009/dsa-1925
→
http://www.mandriva.com/security/advisories?name=MDVSA-2009:288
→
http://www.securityfocus.com/bid/36804Patch
→
https://bugzilla.redhat.com/show_bug.cgi?id=530719Patch
→
https://exchange.xforce.ibmcloud.com/vulnerabilities/53936
→
https://www.redhat.com/archives/fedora-package-announce/2009-November/msg00642.html
→
https://www.redhat.com/archives/fedora-package-announce/2009-November/msg00649.html
→
http://bugs.proftpd.org/show_bug.cgi?id=3275
→
http://marc.info/?l=oss-security&m=125630966510672&w=2
→
http://marc.info/?l=oss-security&m=125632960508211&w=2

Quick Facts

CVE IDCVE-2009-3639
CVSS Score5.8 / 10
SeverityMEDIUM
WeaknessCWE-310
CISA KEVNo
Affected1 vendor(s)
PublishedOct 28, 2009

Related CVEs (CWE-310)

CVE-2007-6521
10.0
CVE-2011-0935
10.0
CVE-2009-1174
10.0
CVE-2009-1472
10.0
CVE-2008-7252
10.0
CVE-2012-2405
10.0

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2009-3639 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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