BlackTreeIndependent security intelligence
← Back to the CVE catalogue
Full vulnerability report · 2020
CVE-2020-9273High confidence

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

n/a · n/a

8.8HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
SSA-679335 · CSAF 2.0 · revision 2 · finalSiemens ProductCERTSSA-679335: Multiple Vulnerabilities in Embedded FTP Server of SIMATIC CP Modules
2 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • SIMATIC CP 1543-1 (incl. SIPLUS variants)
  • SIMATIC CP 1545-1
Summary
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.
Remediation
Update to V3.0 or later version
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2020-30102

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

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.

What

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.

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.

What

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.

Why

The program can continue using memory after it has been released, producing unsafe and attacker-influenceable behaviour.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Use After Free → execute code or commands in the affected security context
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-416 ↗

CWE-416: Use After Free. The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
NetworkRemote code executionCWE-416
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

CERT-FR · French · CERTFR-2022-AVI-547Multiples vulnérabilités dans les produits Siemens

ssa-764417 du 14 juin 2022 https://cert-portal.siemens.com/productcert/html/ssa-764417.html Bulletin de sécurité Siemens ssa-911567 du 14 juin 2022 https://cert-portal.siemens.com/productcert/html/ssa-911567.html Bulletin de sécurité Siemens ssa-988345 du 14 juin 2022 https://cert-portal.siemens.com/productcert/html/ssa-988345.html Référence CVE CVE-2017-9946 https://www.cve.org/CVERecord?id=CVE-2017-9946 Référence CVE CVE-2017-9947 https://www.cve.org/CVERecord?id=CVE-2017-9947 Référence CVE CVE-2020-27304 https://www.cve.org/CVERecord?id=CVE-2020-27304 Référence CVE CVE-2020-9272 https://www.cve.org/CVERecord?id=CVE-2020-9272 Référence CVE CVE-2020-9273 https://www.cve.org/CVERecord?id=CVE-2020-9273 Référence CVE CVE-2021-20317 https://www.cve.org/CVERecord?id=CVE-2021-20317 Référence CVE CVE-2021-22924 https://www.cve.org/CVERecord?id=CVE-2021-22924 Référence CVE CVE-2021-22925 https://www.cve.org/CVERecord?id=CVE-2021-22925 Référence CVE CVE-2021-33196 https://www.cve.org/CVERecord?id=CVE-2021-33196 Référence CVE CVE-2021-33910 https://www.cve.org/CVERecord?id=CVE-2021-33910 Référence CVE CVE-2021-34798 https://www.cve.org/CVERecord?id=CVE-2021-34798 Référence CVE CVE-2021-36221 https://www.cve.org/CVERecord?id=CVE-2021-36221 Référence CVE CVE-2021-37182 https://www.cve.org/CVERecord?id=C

Official advisory
CERT-FR · French · CERTFR-2021-AVI-608Multiples vulnérabilités dans les produits Siemens

CVERecord?id=CVE-2020-24507 Référence CVE CVE-2020-24511 https://www.cve.org/CVERecord?id=CVE-2020-24511 Référence CVE CVE-2020-24512 https://www.cve.org/CVERecord?id=CVE-2020-24512 Référence CVE CVE-2020-24513 https://www.cve.org/CVERecord?id=CVE-2020-24513 Référence CVE CVE-2020-28397 https://www.cve.org/CVERecord?id=CVE-2020-28397 Référence CVE CVE-2020-8670 https://www.cve.org/CVERecord?id=CVE-2020-8670 Référence CVE CVE-2020-8703 https://www.cve.org/CVERecord?id=CVE-2020-8703 Référence CVE CVE-2020-8704 https://www.cve.org/CVERecord?id=CVE-2020-8704 Référence CVE CVE-2020-9272 https://www.cve.org/CVERecord?id=CVE-2020-9272 Référence CVE CVE-2020-9273 https://www.cve.org/CVERecord?id=CVE-2020-9273 Référence CVE CVE-2021-25659 https://www.cve.org/CVERecord?id=CVE-2021-25659 Référence CVE CVE-2021-32936 https://www.cve.org/CVERecord?id=CVE-2021-32936 Référence CVE CVE-2021-32938 https://www.cve.org/CVERecord?id=CVE-2021-32938 Référence CVE CVE-2021-32940 https://www.cve.org/CVERecord?id=CVE-2021-32940 Référence CVE CVE-2021-32944 https://www.cve.org/CVERecord?id=CVE-2021-32944 Référence CVE CVE-2021-32946 https://www.cve.org/CVERecord?id=CVE-2021-32946 Référence CVE CVE-2021-32948 https://www.cve.org/CVERecord?id=CVE-2021-32948 Référence CVE CVE-2021-32950 https://www.cve.org/CVERecord?id=C

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
SIMATIC CP 1543-1 (incl. SIPLUS variants); SIMATIC CP 1545-1
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
Update to V3.0 or later version
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 20 Feb 2020 · Last source change 4 Aug 2024, 10:26 UTC · CWE-416 · Use After Free

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2020-30102
Product sourceVendor CSAF · Siemens ProductCERT
Remediation sourceVendor CSAF · Siemens ProductCERT
CWE sourceNIST NVD
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →

No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.

Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2020-30102↗Vendor CSAF · Siemens ProductCERT↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2020-9273 · cve.blacktree.nl