Debian LinuxOperating system · Debian
CVE-2020-9273
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceProFTPD 1.3.7 contains a use-after-free vulnerability in the alloc_pool function in pool.c. An attacker can corrupt the memory pool by interrupting the data transfer channel, leading to a use-after-free condition that may allow remote code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
Debian LinuxOperating system
= 8.0= 9.0= 10.0
FedoraOperating system
= 30= 31= 1.3.7= 15.0= 15.1all versions< 3.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Confirm ProFTPD is installedRun 'proftpd -v' or check for the proftpd package using your system package manager (dpkg -l | grep proftpd, rpm -qa | grep proftpd)Affected if ProFTPD is present on the system
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Identify the ProFTPD versionExecute 'proftpd -v' and note the exact version number displayedAffected if The version is 1.3.7 (matches the affected version exactly)
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Check if FTP data transfer features are in useReview the proftpd configuration file (commonly /etc/proftpd/proftpd.conf or /etc/proftpd.conf) for active TransferRate, AllowRetrieveRestart, or similar data transfer directivesAffected if The server is configured to handle active FTP data transfers which trigger the vulnerable alloc_pool code path
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Verify the server is reachable and accepting connectionsTest FTP connectivity to the server using an FTP client or network scan tool to confirm the service is exposedAffected if ProFTPD is running and accessible on the network, allowing potential attackers to initiate data transfer interruptions
A system is affected if it runs ProFTPD version 1.3.7 and has FTP data transfer capabilities enabled, as the use-after-free in alloc_pool triggers when the data transfer channel is interrupted.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor data3.0
Upgrade to a patched version of ProFTPD. If immediate upgrade is not feasible, restrict or monitor FTP access to mitigate exploitation attempts.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,480.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-9273 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-9273 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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