CVE-2020-9273

In 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 in pool.c, and possible remote code execution.

Published: 2020-02-20 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-9273 is rated High Risk (68.5/100): CVSS High severity, with high exploitation likelihood (EPSS 60.22%, 98th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-9273

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-02 61.31% 60.22% -1.08%
2 2026-05-27 62.28% 61.31% -0.98%
3 2026-05-03 — 62.28% —

Full EPSS history (35 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-9273

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 [email protected]
9.0 2.0 HIGH
AV:N/AC:L/Au:S/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 8.0 10.0 [email protected]

Weakness enumeration for CVE-2020-9273

OS Trackers for CVE-2020-9273

vendor priority summary link
debian not yet assigned CVE-2020-9273 not yet assigned priority: Debian including 1 source packages (proftpd-dfsg), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-9273
gentoo normal CVE-2020-9273: 1 GLSA(s) (202003-35), 1 atom(s) (net-ftp/proftpd); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2020-9273
ubuntu medium CVE-2020-9273 medium priority: Ubuntu including 1 source packages (proftpd-dfsg), 17 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 12, needed 2, DNE 1, ignored 1, released 1. https://ubuntu.com/security/CVE-2020-9273

Affected software / configurations for CVE-2020-9273

Vendor Product Version Raw CPE
proftpd proftpd 1.3.7 cpe:2.3:a:proftpd:proftpd:1.3.7:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
fedoraproject fedora 30 cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*
fedoraproject fedora 31 cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*
opensuse backports_sle 15.0 cpe:2.3:a:opensuse:backports_sle:15.0:-:*:*:*:*:*:*
opensuse backports_sle 15.0 cpe:2.3:a:opensuse:backports_sle:15.0:sp1:*:*:*:*:*:*
opensuse leap 15.1 cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*
siemens simatic_net_cp_1545-1_firmware — cpe:2.3:o:siemens:simatic_net_cp_1545-1_firmware:-:*:*:*:*:*:*:*
siemens simatic_net_cp_1543-1_firmware < 3.0 cpe:2.3:o:siemens:simatic_net_cp_1543-1_firmware:*:*:*:*:*:*:*:*

References for CVE-2020-9273

URL Tags
http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00002.html Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/08/25/1 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/06/2 Mailing List Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-679335.pdf Third Party Advisory
https://github.com/proftpd/proftpd/blob/master/RELEASE_NOTES Release Notes Third Party Advisory
https://github.com/proftpd/proftpd/issues/903 Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/02/msg00022.html Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2020/03/msg00002.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/VCUPRYSJR7XOM3HQ6H5M4OGDU7OHCHBF/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XHO3S5WPRRP7VGKIAHLYQVEYW5HRYIJN/
https://security.gentoo.org/glsa/202003-35 Third Party Advisory
https://www.debian.org/security/2020/dsa-4635 Third Party Advisory
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