How severe is CVE-2020-15152?

CVE-2020-15152 has a CVSS score of 9.1/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-15152?

CVE-2020-15152 affects the following packages: ftp-srv (npm), ftp-srv (npm), ftp-srv (npm). Ecosystems affected: npm.

How do I fix CVE-2020-15152?

Update ftp-srv to 2.19.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15152 is resolved across your whole dependency graph.

How do I detect CVE-2020-15152 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ftp-srv, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2020-15152 if there is no patch (or I can't update yet)?

Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Is CVE-2020-15152 actively exploited in the wild?

No public exploit code has been indexed for CVE-2020-15152 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2020-15152?

CVE-2020-15152 has an EPSS (Exploit Prediction Scoring System) score of 1.9%, placing it in the 79th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2020-15152?

CVE-2020-15152 is classified as Server-Side Request Forgery (SSRF) (CWE-918). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2020-15152 published, and has it been updated?

CVE-2020-15152 was published on August 17, 2020 and was last updated on August 27, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

CRITICAL severity

CVE-2020-15152 — ftp-srv

CRITICALFix: autovance/ftp-srv@e449e75

CVE-2020-15152 is a critical-severity (CVSS 9.1) Server-Side Request Forgery (SSRF) vulnerability in ftp-srv. A fix is available for ftp-srv — see the affected versions and patch details below.

Server-Side Request Forgery in ftp-srv

Also known asGHSA-jw37-5gqr-cf9j

Published

Aug 17, 2020

Updated

Aug 27, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Oct 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs79th percentile — riskier than 79% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2020-15152 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

3 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

29other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

ftp-srvnpm

22Kdownloads / week

Description

Background

The FTP protocol creates two connections, one for commands and one for transferring data. This second data connection can be created in two ways, on the server by sending the PASV command, or on the client by sending the PORT command.

The PORT command sends the IP and port for the server to connect to the client with.

Issue

Since the client can send an arbitrary IP with the PORT command, this can be used to cause the server to make a connection elsewhere.

Patches

fix: disallow PORT connections to alternate hosts: e449e75219d918c400dec65b4b0759f60476abca

Deprecation notices have been published for older versions.

Workarounds

Blacklisting the FTP Command PORT will prevent the server from exposing this behaviour through active connections until a fix is applied.

const ftp = new FtpSrv({
  blacklist: ['PORT']
});

References

https://www.npmjs.com/advisories/1445

Credits

Thank you to; @trs for fixing it @andreeleuterio for reporting it to us for an anonymous user (Vincent) through the NPM platform @quiquelhappy for bringing it to our attention after it slipped through the cracks during Christmas

For more information

If you have any questions or comments about this advisory:

Open an issue at https://github.com/autovance/ftp-srv
Email us directly; [email protected]

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`ftp-srv`	≥ 1.0.0&&< 2.19.6	2.19.6`npm install ftp-srv@2.19.6`
📦npm	`ftp-srv`	≥ 3.0.0&&< 3.1.2	3.1.2`npm install ftp-srv@3.1.2`
📦npm	`ftp-srv`	≥ 4.0.0&&< 4.3.4	4.3.4`npm install ftp-srv@4.3.4`

Affected Products

1 product · 3 configurations

Application

ftp-srvftp-srv_project

≥ 4.0.0 && < 4.3.4

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ftp-srv, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update ftp-srv to 2.19.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-15152 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Frequently Asked Questions

### Background The FTP protocol creates two connections, one for commands and one for transferring data. This second data connection can be created in two ways, on the server by sending the PASV command, or on the client by sending the PORT command. The PORT command sends the IP and port for the server to connect to the client with. ### Issue Since the client can send an arbitrary IP with the PORT command, this can be used to cause the server to make a connection elsewhere. ### Patches * _fix: disallow PORT connections to alternate hosts_: e449e75219d918c400dec65b4b0759f60476abca Depreca