CVE-2020-9273· NVD / CVE Program· CNA mitre

In ProFTPD 1.3.7, it is possible to corrupt the memory pool by interrupting the data transfer channel.

Noroxi assessment

Priority: Monitor (action score 39/100)

Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 12.1% (FIRST EPSS); higher than 96.1% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
Fixed version: proftpd-dfsg (Debian:10) 1.3.6-4+deb10u4; proftpd-dfsg (Debian:12) 1.3.6c-2; proftpd-dfsg (Debian:8) 1.3.5e+r1.3.5-2+deb8u7, 1.3.5e+r1.3.5-2+deb8u6.
Mentioned 4 times in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to proftpd-dfsg (Debian:10) 1.3.6-4+deb10u4; proftpd-dfsg (Debian:12) 1.3.6c-2; proftpd-dfsg (Debian:8) 1.3.5e+r1.3.5-2+deb8u7, 1.3.5e+r1.3.5-2+deb8u6 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 8.8 · v3.1—Proof of concept Fix available

Published: Feb 20, 2020
Updated: Jun 16, 2026
EPSS: 12.1% · 96th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 4 / 30 · 12.1%

Get told when this record changes

Not in KEV: no record of exploitation in the wild
Proof of concept exists, no weaponized module
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
proftpd	proftpd	cpe:2.3:a:proftpd:proftpd
debian	debian linux	cpe:2.3:o:debian:debian_linux
fedoraproject	fedora	cpe:2.3:o:fedoraproject:fedora
opensuse	backports sle	cpe:2.3:a:opensuse:backports_sle
opensuse	leap	cpe:2.3:o:opensuse:leap
siemens	simatic net cp 1545-1 firmware	cpe:2.3:o:siemens:simatic_net_cp_1545-1_firmware
siemens	simatic net cp 1545-1	cpe:2.3:h:siemens:simatic_net_cp_1545-1
siemens	simatic net cp 1543-1 firmware	cpe:2.3:o:siemens:simatic_net_cp_1543-1_firmware
siemens	simatic net cp 1543-1	cpe:2.3:h:siemens:simatic_net_cp_1543-1

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

debian debian linux10.0
debian debian linux8.0
debian debian linux9.0
fedoraproject fedora30
fedoraproject fedora31
opensuse backports sle15.0
opensuse leap15.1
proftpd proftpd1.3.7
siemens simatic net cp 1543-1 firmwarebefore 3.0
siemens simatic net cp 1545-1 firmwareall versions

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:10	proftpd-dfsg	before 1.3.6-4+deb10u4	1.3.6-4+deb10u4
Debian:12	proftpd-dfsg	before 1.3.6c-2	1.3.6c-2
Debian:8	proftpd-dfsg	before 1.3.5e+r1.3.5-2+deb8u7	1.3.5e+r1.3.5-2+deb8u7
Debian:8	proftpd-dfsg	before 1.3.5e+r1.3.5-2+deb8u6	1.3.5e+r1.3.5-2+deb8u6
Debian:9	proftpd-dfsg	before 1.3.5b-4+deb9u4	1.3.5b-4+deb9u4
openSUSE:Leap 15.1	proftpd	before 1.3.6c-bp151.4.9.1	1.3.6c-bp151.4.9.1
openSUSE:Tumbleweed	proftpd	before 1.3.6e-1.10	1.3.6e-1.10
SUSE:Package Hub 15	proftpd	before 1.3.6c-bp151.4.9.1	1.3.6c-bp151.4.9.1

Same product

proftpd: all records

Other highest-scoring records for the same primary product.

CVE-2015-3306The 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.KEV
100Now
CVE-2010-4221Multiple stack-based buffer overflows in the pr_netio_telnet_gets function in netio.c in ProFTPD before 1.3.3c allow remote attackers to exe
67This week
CVE-2010-20103ProFTPD 1.3.3c Backdoor Command Execution
60This week

Published before and after this one in the same product

← EarlierCVE-2019-19269Nov 30, 2019 · An issue was discovered in tls_verify_crl in ProFTPD through 1.3.6b.
19Monitor
← EarlierCVE-2020-9272Feb 20, 2020 · ProFTPD 1.3.7 has an out-of-bounds (OOB) read vulnerability in mod_cap via the cap_text.c cap_to_text function.
31Monitor
Later →CVE-2021-46854Nov 23, 2022 · mod_radius in ProFTPD before 1.3.7c allows memory disclosure to RADIUS servers because it copies blocks of 16 characters.
30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
debian:proftpd-dfsg	1.3.6c-2 · Debian:12	Package registry (OSV)
opensuse:proftpd	1.3.6c-bp151.4.9.1 · openSUSE:Leap 15.1	Package registry (OSV)
suse:proftpd	1.3.6c-bp151.4.9.1 · SUSE:Package Hub 15	Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Proof-of-concept repository on GitHub	stars:14	2020-11-05

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedFeb 20, 2020
First PoCNov 5, 2020+258 d
TodayOct 23, 2026+2437 d

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-21-0628 · Aug 11, 2021(Siemens Güvenlik Güncellemesi)
TR-20-633 · Aug 24, 2020(Proftpd Sunucu Güvenlik Güncellemesi)
TR-20-114 · Feb 26, 2020(Proftpd Sunucu Güvenlik Güncellemesi)
TR-20-111 · Feb 20, 2020(Proftpd Sunucu Güvenlik Güncellemesi)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:45 PM UTC

For records you follow, these changes also arrive as notifications. →

References

lists.opensuse.org/opensuse-security-announce/2020-03/msg00002.html

Show all references (11 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records