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Vulnerability record · CVE-2009-3639 · published 28 October 2009

CVE-2009-3639: Proftpd vulnerability

PProftpd · Proftpd

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.

5.8 CVSS 2.0 Medium EPSS 5.7% · top 7.3% CWE-310 · CWE-310
5.8CVSS 2.0 base score
5.7%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
24References
16 Jun 2026Last modified by NVD

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.

AV:N/AC:M/Au:N/C:N/I:P/A:P

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
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/37131 Vendor 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/36804 Patch
https://bugzilla.redhat.com/show_bug.cgi?id=530719 Patch
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
http://secunia.com/advisories/37131 Vendor 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/36804 Patch
https://bugzilla.redhat.com/show_bug.cgi?id=530719 Patch
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

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

10.0CVE-2015-3306ProFTPD mod_copy arbitrary file read and writeThe mod_copy module in ProFTPD 1.3.5 fails to restrict the SITE CPFR and SITE CPTO commands, letting remote attackers copy arbitrary files on the ser…EPSS 97%analysed10.0CVE-2010-4221ProFTPD TELNET IAC handling stack buffer overflow allows remote code executionProFTPD before 1.3.3c contains multiple stack-based buffer overflows in the pr_netio_telnet_gets function in netio.c. A remote attacker can trigger t…EPSS 91%analysed9.8CVE-2019-12815ProFTPD mod_copy arbitrary file copy enables unauthenticated RCEmod_copy in ProFTPD up to 1.3.5b performs an arbitrary file copy without validating the source or destination, letting an unauthenticated remote clie…EPSS 58%analysed9.3CVE-2010-20103Proftpd vulnerabilityA malicious backdoor was embedded in the official ProFTPD 1.3.3c source tarball distributed between November 28 and December 2, 2010. The backdoor im…EPSS 5.1%9.0CVE-2011-4130Proftpd vulnerabilityUse-after-free vulnerability in the Response API in ProFTPD before 1.3.3g allows remote authenticated users to execute arbitrary code via vectors inv…EPSS 13%8.8CVE-2020-9273Proftpd use after free vulnerabilityIn ProFTPD 1.3.7, it is possible to corrupt the memory pool by interrupting the data transfer channel. This triggers a use-after-free in alloc_pool i…EPSS 12%8.7CVE-2026-63090Proftpd heap-based buffer overflow vulnerabilityProFTPD before 1.3.9c and 1.3.10rc3 contains a heap-based buffer overflow vulnerability in the mod_sftp module that allows authenticated low-privileg…EPSS 0.93%8.6CVE-2026-35025Proftpd link following vulnerabilityProFTPD through 1.3.9b and 1.3.10rc2 contains an access control bypass vulnerability that allows authenticated FTP users to circumvent Directory ACL …EPSS 0.51%

Source: NIST National Vulnerability Database (record CVE-2009-3639), CISA KEV, FIRST EPSS (scores of 2026-09-28). This page is refreshed as NVD updates the record.