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Fencer Vulns
low 3.7

CVE-2021-22924 json

libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse, if...

published 2021-08-05 5 y ago modified 2026-10-14 26 d ago also EUVD-2021-10053 , JLSEC-2025-28

cvss
3.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
6.3%
EPSS 6.3% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

libcurl keeps previously used connections in a connection pool for subsequenttransfers to reuse, if one of them matches the setup.Due to errors in the logic, the config matching function did not take 'issuercert' into account and it compared the involved paths *case insensitively*,which could lead to libcurl reusing wrong connections.File paths are, or can be, case sensitive on many systems but not all, and caneven vary depending on used file systems.The comparison also didn't include the 'issuer cert' which a transfer can setto qualify how to verify the server certificate.

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 7.79.1-1

debian advisories DEBIAN-CVE-2021-22924

  • curl Ubuntu 18.04 LTS 7.58.0-2ubuntu3.14
  • curl Ubuntu 20.04 LTS 7.68.0-1ubuntu2.6

ubuntu advisories UBUNTU-CVE-2021-22924

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

  • rh-dotnet31-curl RHEL 3.1 DOTNET 7.61.1-22.el7_9
  • rh-dotnet31-libcurl RHEL 3.1 DOTNET 7.61.1-22.el7_9
  • curl RHEL 8 7.61.1-18.el8_4.1
  • libcurl RHEL 8 7.61.1-18.el8_4.1
  • libcurl-minimal RHEL 8 7.61.1-18.el8_4.1

red hat advisories RHSA-2022:1354RHSA-2021:3582

  • curl SLES for SAP 12 SP5, SLES 12 SP5, SLE Software Development Kit 12 SP5 7.60.0-11.23.1
  • curl SLES for SAP 15 SP1, SLES for SAP 15, SLES 15-LTSS +10 more 7.60.0-3.47.1
  • curl SLE Module for Basesystem 15 SP3, SLE Module for Basesystem 15 SP2, SLE Micro 5.0 7.66.0-4.22.1
  • curl-openssl1 SLES 11-SECURITY 7.37.0-70.71.1
  • curl SLES for SAP 12 SP4, SLES 12 SP4-LTSS, OpenStack Cloud Crowbar 9 +1 more 7.60.0-4.25.1

suse advisories SUSE-SU-2021:2462-1SUSE-SU-2021:2440-1SUSE-SU-2021:2439-1SUSE-SU-2021:14768-1SUSE-SU-2021:2425-1

  • curl openSUSE Tumbleweed 7.79.1-1.1
  • curl openSUSE Leap 15.2 7.66.0-lp152.3.21.1
  • curl-mini openSUSE Leap 15.2 7.66.0-lp152.3.21.1
  • curl openSUSE Leap 15.3 7.66.0-4.22.1

opensuse advisories openSUSE-SU-2024:10582-1openSUSE-SU-2021:1088-1openSUSE-SU-2021:2439-1

  • curl Rocky Linux 8 7.61.1-18.el8_4.1

rocky linux advisories RLSA-2021:3582

  • curl Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 7.78.0-r0

alpine advisories ALPINE-CVE-2021-22924

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 CBL-Mariner 2.0 7.76.0-5

azure linux advisories AZL-6367

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

  • curl Arch Linux 7.78.0-1
  • lib32-curl Arch Linux 7.78.0-1
  • libcurl-compat Arch Linux 7.78.0-1
  • lib32-libcurl-compat Arch Linux 7.78.0-1
  • libcurl-gnutls Arch Linux 7.78.0-1
  • lib32-libcurl-gnutls Arch Linux 7.78.0-1

arch linux advisories AVG-2194AVG-2195AVG-2196AVG-2197AVG-2198AVG-2199

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-2021-22924 updated cvss 3.7

curl: Bad connection reuse due to flawed path name checks

  • Red Hat .NET Core 2.1 on Red Hat Enterprise Linux rh-dotnet21-curl, rh-dotnet21-libcurl Red Hat Ceph Storage 2 curl, libcurl Red Hat Enterprise Linux 6 curl, libcurl Red Hat Enterprise Linux 7 curl, libcurl
    affected: workaround, no fix planned “This flaw can be mitigated by upgrading the affected curl utility to version 7.78.0”
  • Red Hat JBoss Core Services jbcs-httpd24-curl jbcs-httpd24-curl
    affected: workaround, no fix available “This flaw can be mitigated by upgrading the affected curl utility to version 7.78.0”
  • Red Hat Software Collections httpd24-curl, httpd24-libcurl
    affected: workaround, no fix planned “This flaw can be mitigated by upgrading the affected curl utility to version 7.78.0”
  • Red Hat .NET Core on Red Hat Enterprise Linux ComputeNode (v. 7) rh-dotnet31-curl 7.61.1-22.el7_9, rh-dotnet31-libcurl 7.61.1-22.el7_9 Red Hat .NET Core on Red Hat Enterprise Linux Server (v. 7) rh-dotnet31-curl 7.61.1-22.el7_9, rh-dotnet31-libcurl 7.61.1-22.el7_9 Red Hat .NET Core on Red Hat Enterprise Linux Workstation (v. 7) rh-dotnet31-curl 7.61.1-22.el7_9, rh-dotnet31-libcurl 7.61.1-22.el7_9
    fixed: vendor fix “This flaw can be mitigated by upgrading the affected curl utility to version 7.78.0” RHSA-2022:1354
  • Red Hat Enterprise Linux BaseOS (v. 8) curl 7.61.1-18.el8_4.1, libcurl 7.61.1-18.el8_4.1, libcurl-minimal 7.61.1-18.el8_4.1
    fixed: vendor fix “This flaw can be mitigated by upgrading the affected curl utility to version 7.78.0” RHSA-2021:3582
  • Red Hat Enterprise Linux 9 curl, libcurl, curl-minimal, libcurl-minimal
    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 ICSA-22-167-17 updated cvss 3.7

Siemens OpenSSL Affecting Industrial Products

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

cisa ICSA-22-132-13 updated cvss 3.7

Siemens Industrial Devices using libcurl

  • Siemens LOGO! CMR family
    affected: mitigation, no fix planned
  • Siemens RUGGEDCOM RM1224 LTE(4G) EU <V7.1 Siemens RUGGEDCOM RM1224 LTE(4G) NAM <V7.1 Siemens SCALANCE M804PB <V7.1 Siemens SCALANCE M812-1 ADSL-Router (Annex A) <V7.1 Siemens SCALANCE M812-1 ADSL-Router (Annex B) <V7.1 Siemens SCALANCE M816-1 ADSL-Router (Annex A) <V7.1
    +11 more products
    Siemens SCALANCE M816-1 ADSL-Router (Annex B) <V7.1 Siemens SCALANCE M826-2 SHDSL-Router <V7.1 Siemens SCALANCE M874-2 <V7.1 Siemens SCALANCE M874-3 <V7.1 Siemens SCALANCE M876-3 (EVDO) <V7.1 Siemens SCALANCE M876-3 (ROK) <V7.1 Siemens SCALANCE M876-4 (EU) <V7.1 Siemens SCALANCE M876-4 (NAM) <V7.1 Siemens SCALANCE MUM856-1 (EU) <V7.1 Siemens SCALANCE MUM856-1 (RoW) <V7.1 Siemens SCALANCE S615 <V7.1
    affected: fixed in V7.1 support.industry.siemens.com
  • Siemens SIMATIC CP 1242-7 V2 <V3.3.46 Siemens SIMATIC CP 1243-1 <V3.3.46 Siemens SIMATIC CP 1243-7 LTE EU <V3.3.46 Siemens SIMATIC CP 1243-7 LTE US <V3.3.46 Siemens SIMATIC CP 1243-8 IRC <V3.3.46
    affected: fixed in V3.3.46 support.industry.siemens.com
  • Siemens SIMATIC CP 1543-1 <V3.0.22
    affected: fixed in V3.0.22 support.industry.siemens.com
  • Siemens SIMATIC CP 1545-1 <V1.1
    affected: fixed in V1.1 support.industry.siemens.com
  • Siemens SIMATIC RTU3010C <V5.0.14 Siemens SIMATIC RTU3030C <V5.0.14 Siemens SIMATIC RTU3031C <V5.0.14 Siemens SIMATIC RTU3041C <V5.0.14
    affected: fixed in V5.0.14 support.industry.siemens.com
  • Siemens SINEMA Remote Connect Client <V3.1
    affected: fixed in V3.1 support.industry.siemens.com
  • Siemens SIPLUS NET CP 1242-7 V2 <V3.3.46
    affected: fixed in V3.3.46 support.industry.siemens.com
show 2 more

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
2 y ago

Exploit prediction

6.27% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • hackerone.com https://hackerone.com/reports/1223565 referenced PoC, tagged "exploit" by a source, unverified

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-20 Improper Input Validation
  • CWE-706 Use of Incorrectly-Resolved Name or Reference
Technology feeds

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.