Skip to content
Fencer Vulns
low 3.7

CVE-2020-8284 json

A malicious server can use the FTP PASV response to trick curl 7.73.0 and earlier into connecting back to a given IP address and port, and…

published 2020-12-14 5 y ago modified 2026-10-14 26 d ago also EUVD-2020-29152 , JLSEC-2026-1332

cvss
3.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
3.9%
EPSS 3.9% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

A malicious server can use the FTP PASV response to trick curl 7.73.0 and earlier into connecting back to a given IP address and port, and this way potentially make curl extract information about services that are otherwise private and not disclosed, for example doing port scanning and service banner extractions.

Patch / fix

  • julia LibCURL_jll 7.81.0+0
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP V3.1.5
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP V3.1.5
  • curl Debian 14, Debian 13, Debian 12 7.74.0-1

debian advisories DEBIAN-CVE-2020-8284

  • curl Ubuntu 16.04 LTS 7.47.0-1ubuntu2.18
  • curl Ubuntu 18.04 LTS 7.58.0-2ubuntu3.12
  • curl Ubuntu 20.04 LTS 7.68.0-1ubuntu2.4
  • curl Ubuntu Pro 14.04 LTS 7.35.0-1ubuntu2.20+esm6

ubuntu advisories UBUNTU-CVE-2020-8284

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • jbcs-httpd24 jboss core services 1 1-18.jbcs.el7
  • jbcs-httpd24 jboss core services 1 1-18.el8jbcs
  • jbcs-httpd24-apr jboss core services 1 1.6.3-105.jbcs.el7
  • jbcs-httpd24-apr jboss core services 1 1.6.3-105.el8jbcs
  • jbcs-httpd24-curl jboss core services 1 7.77.0-2.jbcs.el7
  • jbcs-httpd24-curl jboss core services 1 7.77.0-2.el8jbcs
  • jbcs-httpd24-httpd jboss core services 1 2.4.37-74.jbcs.el7
  • jbcs-httpd24-httpd jboss core services 1 2.4.37-74.el8jbcs

red hat advisories RHSA-2021:2472RHSA-2021:1610

  • curl SLES for SAP 12 SP4, SLES 12 SP4-LTSS, OpenStack Cloud Crowbar 9 +1 more 7.60.0-4.20.1
  • curl-openssl1 SLES 11-SECURITY 7.37.0-70.57.1
  • curl SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 7.60.0-11.9.1
  • curl SLE Module for Basesystem 15 SP2 7.66.0-4.11.1
  • curl SLE Module for Basesystem 15 SP1 7.60.0-3.35.1

suse advisories SUSE-SU-2021:1786-1SUSE-SU-2020:14585-1SUSE-SU-2020:3739-1SUSE-SU-2020:3735-1SUSE-SU-2020:3733-1

  • curl openSUSE Tumbleweed 7.79.1-1.1
  • curl openSUSE Leap 15.1 7.60.0-lp151.5.18.1
  • curl-mini openSUSE Leap 15.1 7.60.0-lp151.5.18.1
  • curl openSUSE Leap 15.2 7.66.0-lp152.3.12.1
  • curl-mini openSUSE Leap 15.2 7.66.0-lp152.3.12.1

opensuse advisories openSUSE-SU-2024:10582-1openSUSE-SU-2020:2249-1openSUSE-SU-2020:2238-1

  • curl Rocky Linux 8 7.61.1-18.el8

rocky linux advisories RLSA-2021:1610

  • curl Alpine 3.11 7.79.0-r0
  • curl Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 7.74.0-r0

alpine advisories ALPINE-CVE-2020-8284

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • curl Arch Linux 7.74.0-1

arch linux advisories AVG-1337

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-8284 updated cvss 3.1

curl: FTP PASV command response can cause curl to connect to arbitrary host

  • Red Hat Ceph Storage 2 curl, libcurl Red Hat Enterprise Linux 5 curl Red Hat Enterprise Linux 6 curl, libcurl Red Hat Enterprise Linux 7 curl, libcurl
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Software Collections httpd24-curl, httpd24-libcurl
    affected: workaround, no fix planned “Will not fix”
  • Red Hat JBoss Core Services Apache HTTP Server 2.4.37 SP8
    fixed: vendor fix RHSA-2021:2471
  • Red Hat Enterprise Linux BaseOS (v. 8) curl 7.61.1-18.el8, libcurl 7.61.1-18.el8, libcurl-minimal 7.61.1-18.el8
    fixed: vendor fix RHSA-2021:1610
  • Red Hat JBoss Core Services on RHEL 7 Server jbcs-httpd24 1-18.jbcs.el7, jbcs-httpd24-runtime 1-18.jbcs.el7, jbcs-httpd24-apr 1.6.3-105.jbcs.el7, jbcs-httpd24-curl 7.77.0-2.jbcs.el7, jbcs-httpd24-httpd 2.4.37-74.jbcs.el7, jbcs-httpd24-jansson 2.11-55.jbcs.el7, +23 more Red Hat JBoss Core Services on RHEL 8 jbcs-httpd24 1-18.el8jbcs, jbcs-httpd24-runtime 1-18.el8jbcs, jbcs-httpd24-apr 1.6.3-105.el8jbcs, jbcs-httpd24-curl 7.77.0-2.el8jbcs, jbcs-httpd24-brotli 1.0.6-40.el8jbcs, jbcs-httpd24-httpd 2.4.37-74.el8jbcs, +30 more
    fixed: vendor fix RHSA-2021:2472
  • Red Hat .NET Core 2.1 on Red Hat Enterprise Linux rh-dotnet21-curl, rh-dotnet21-libcurl Red Hat .NET Core 3.1 on Red Hat Enterprise Linux rh-dotnet31-curl, rh-dotnet31-libcurl
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-23-348-10 updated cvss 3.7

Siemens SIMATIC S7-1500

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.0, < 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.0, < 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.0, < 3.1.5
    affected: fixed in V3.1.5, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
6 mo ago

Exploit prediction

3.90% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
CNA 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N
OSV 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
julia LibCURL_jll
<7.81.0+0
7.81.0+0

Affected products

  • n/a https://github.com/curl/curl
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.