Skip to content
Fencer Vulns
high 7.5

CVE-2020-8231 json

Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when...

published 2020-12-14 5 y ago modified 2026-11-02 6 d ago also EUVD-2020-29103 , JLSEC-2025-23

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.3%
EPSS 5.3% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

Due to use of a dangling pointer, libcurl 7.29.0 through 7.71.1 can use the wrong connection when sending data.

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 7.72.0-1

debian advisories DEBIAN-CVE-2020-8231

  • curl Ubuntu 16.04 LTS 7.47.0-1ubuntu2.16
  • curl Ubuntu 18.04 LTS 7.58.0-2ubuntu3.10
  • curl Ubuntu 20.04 LTS 7.68.0-1ubuntu2.2
  • curl Ubuntu Pro 14.04 LTS 7.35.0-1ubuntu2.20+esm5

ubuntu advisories UBUNTU-CVE-2020-8231

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

  • curl RHEL 8 7.61.1-18.el8
  • libcurl RHEL 8 7.61.1-18.el8
  • libcurl-minimal RHEL 8 7.61.1-18.el8

red hat advisories RHSA-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 7.37.0-70.52.2
  • curl SLE Module for Basesystem 15 SP1 7.60.0-3.32.1
  • curl SLE Module for Basesystem 15 SP2 7.66.0-4.6.1
  • curl SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 7.60.0-11.6.1

suse advisories SUSE-SU-2021:1786-1SUSE-SU-2020:14481-1SUSE-SU-2020:2446-1SUSE-SU-2020:2445-1SUSE-SU-2020:2444-1

  • curl openSUSE Tumbleweed 7.79.1-1.1
  • curl openSUSE Leap 15.2 7.66.0-lp152.3.9.1
  • curl-mini openSUSE Leap 15.2 7.66.0-lp152.3.9.1
  • curl openSUSE Leap 15.2 7.66.0-lp152.3.6.1
  • curl openSUSE Leap 15.1 7.60.0-lp151.5.15.1
  • curl-mini openSUSE Leap 15.1 7.60.0-lp151.5.15.1

opensuse advisories openSUSE-SU-2024:10582-1openSUSE-SU-2020:1494-1openSUSE-SU-2020:1359-1openSUSE-SU-2020:1345-1

  • curl Rocky Linux 8 7.61.1-18.el8

rocky linux advisories RLSA-2021:1610

  • curl Alpine 3.10 7.66.0-r2
  • curl Alpine 3.11 7.67.0-r2
  • curl Alpine 3.12 7.69.1-r2
  • curl Alpine 3.24, Alpine 3.23, Alpine 3.22 +9 more 7.72.0-r0
  • curl Alpine 3.9 7.66.0-r5

alpine advisories ALPINE-CVE-2020-8231

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

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-2020-8231 updated cvss 3.7

curl: Expired pointer dereference via multi API with CURLOPT_CONNECT_ONLY option set

  • Red Hat Ceph Storage 2 curl, libcurl
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 curl, libcurl Red Hat Software Collections httpd24-curl, httpd24-libcurl
    affected: no fix available “Fix deferred”
  • 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 .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 Red Hat Enterprise Linux 5 curl Red Hat Enterprise Linux 6 curl, 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 7.5

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
none
Automatable
no
Technical impact
partial
Assessed
6 d ago

Exploit prediction

5.34% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/948876 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/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

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.