CVE-2019-18217

CVE-2019-18217 is a high-severity vulnerability in Proftpd with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 20% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-835.

Key facts

• Severity: High (CVSS 3.x base score 7.5)
• CVSS v2: 5.0
• EPSS exploit prediction: 20% (97th percentile)
• Actively exploited: Not listed in CISA KEV
• Weakness: CWE-835
• Affected product: Proftpd
• Published: 2019-10-21
• Last modified: 2026-06-17

Description

ProFTPD before 1.3.6b and 1.3.7rc before 1.3.7rc2 allows remote unauthenticated denial-of-service due to incorrect handling of overly long commands because main.c in a child process enters an infinite loop.

Frequently asked questions

What is CVE-2019-18217?

ProFTPD before 1.3.6b and 1.3.7rc before 1.3.7rc2 allows remote unauthenticated denial-of-service due to incorrect handling of overly long commands because main.c in a child process enters an infinite loop.

How severe is CVE-2019-18217?

CVE-2019-18217 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2019-18217 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 20% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-18217?

CVE-2019-18217 primarily affects Proftpd. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-18217?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-18217 published?

CVE-2019-18217 was published on 2019-10-21 and last updated on 2026-06-17.

References

• http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00009.html
• https://cert-portal.siemens.com/productcert/pdf/ssa-940889.pdf
• https://github.com/proftpd/proftpd/blob/1.3.6/NEWS
• https://github.com/proftpd/proftpd/blob/1.3.6/RELEASE_NOTES
• https://github.com/proftpd/proftpd/blob/master/NEWS
• https://github.com/proftpd/proftpd/blob/master/RELEASE_NOTES
• https://github.com/proftpd/proftpd/issues/846
• https://lists.debian.org/debian-lts-announce/2019/10/msg00036.html
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/NJDQRVZTILBX4BUCTIRKP2WBHDHDCJR5/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RB2FPAWDWXT5ALAFIC5Y3RSEMXSFL6H2/
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/YLRPYEEMQJVAXO2SXRGOQ4HBFEEPCNXG/
• https://seclists.org/bugtraq/2019/Nov/7
• https://security.gentoo.org/glsa/202003-35
• https://www.debian.org/security/2019/dsa-4559

Affected products (8)

• cpe:2.3:a:proftpd:proftpd:*:*:*:*:*:*:*:*
• cpe:2.3:a:proftpd:proftpd:1.3.6:-:*:*:*:*:*:*
• cpe:2.3:a:proftpd:proftpd:1.3.6:a:*:*:*:*:*:*
• cpe:2.3:a:proftpd:proftpd:1.3.6:rc1:*:*:*:*:*:*
• cpe:2.3:a:proftpd:proftpd:1.3.6:rc2:*:*:*:*:*:*
• cpe:2.3:a:proftpd:proftpd:1.3.6:rc3:*:*:*:*:*:*
• cpe:2.3:a:proftpd:proftpd:1.3.6:rc4:*:*:*:*:*:*
• cpe:2.3:a:proftpd:proftpd:1.3.7:rc1:*:*:*:*:*:*

More vulnerabilities in Proftpd

• CVE-2015-3306 — Critical (CVSS 10.0): The mod_copy module in ProFTPD 1.3.5 allows remote attackers to read and write to arbitrary files via the site cpfr and…
• CVE-2010-4221 — Critical (CVSS 10.0): Multiple stack-based buffer overflows in the pr_netio_telnet_gets function in netio.c in ProFTPD before 1.3.3c allow…
• CVE-2010-20103 — Critical (CVSS 9.8): A malicious backdoor was embedded in the official ProFTPD 1.3.3c source tarball distributed between November 28 and…
• CVE-2019-12815 — Critical (CVSS 9.8): An arbitrary file copy vulnerability in mod_copy in ProFTPD up to 1.3.5b allows for remote code execution and…
• CVE-2011-4130 — Critical (CVSS 9.0): Use-after-free vulnerability in the Response API in ProFTPD before 1.3.3g allows remote authenticated users to execute…
• CVE-2020-9273 — High (CVSS 8.8): In ProFTPD 1.3.7, it is possible to corrupt the memory pool by interrupting the data transfer channel. This triggers a…

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